The Atom!

Who were the main characters in the development of the atom?

John Dalton, Johannes Hittorf, Sir Joseph John Thompson, James Chadwich, William Conrad Roentgen, Michael Faraday, Robert Millikan, A. van den Broek, Henry Gwyn-Jeffreys Moseley, William Crookes, and Ernst Rutherford

Why were they vital to the development of the atom?

John Dalton created the Atomic Theory. Johannes Hittorf Found out that when a solid was placed between cathode and anode, shadow was cast at the end of test tube away from the cathode. Sir Joseph John Thompson rond cathode rays could be deflected by an electiric field. James Chadwich Proved that neutrons did exsitst. William Conrad Roentgen discovered X-rays. Michael Faraday found Cathode, Metal plate connected to negative end and also Anode which was connected to the positive end. Henry Gwyn-Jeffreys Moseley studied frequencies of an X-rays given off by cathodes. Ernst Rutherford sutdied the absorption of radioactivity. Robert Millikan did the Oil drop experiment. A. Van Den Broek said that a positive charge on atoms shouldnt be compared to their atomic weights it should be compared to the atomic number. William Crookes developed a vacuum pump so he can produce smaller gas pressure on cathode ray tubes.

Why do we consider the atomic theory still a theory?

Theory isnt a law, nor a guess. A theory is saying something that your sure is right and testing it and keep testing it till you get it and make it to a law. Its just been taking longer than relativity. It also applies on the biologival evolution.

What are the new developments?

It started in the late 1700's. the Atomic Theory came into mind aroun 1803 from John Dalton. He said that each kind of element has its own kind of atom. The properties that come with the elements result into their diffrent atoms.

Why does it matter that we understand the structure of the atom?

They matter to us becaus element are all around us and every single one of those elements have thier own atoms. We need to know about atoms because it helps use caculate them easier and even mixed them into compunds or mixtures.

The Atom

Who were the main characters in the development of the atom?
Democritus, John Dalton, J.J. Thompson, Ernst Rutherford, Robert Millikan, Antonius van den Broek, and James Chadwick

Why were they vital to the development of the atom?
-Democritus belived every object was made up little things called atoms; depending on the shape of the atom, the object was a certain uncuttable particle called an atom.
-John Dalton proposed the existence of atoms; also, in 1803, John Dalton created the law of multiple proportions that states that when two elements can combine to form more than one compound the amounts of one of them that combines with a fixed amount of the other will exhibit a simple multiple relation.
-J.J. Thompson found that there must be positively charged particles which also must carry the mass of the atom. Dalton's model is now incorrect because atoms are divisible.
-Ernst Rutherford studied the deflection of alpha particles as they were targetedat thin gold foil sheets. The positive charge and mass of an atom were concentrated in the center and only made up a small fraction of the total volume. He named this concentrated center the nucleus.
-Robert Millikan proved Thomson's hypothesis that the mass of an electron is at least 1000 times smaller than the smallest atom.
-Antonius van den Broek suggested that the positive charge on atoms should be compared to their atomic numbers, not their atomic weights.
-James Chadwick proved that neutrons, neutral particles in the nucleus that made up approximately half the mass of an atom, did exist.



What made them different?
Each experiment performed by the scientists not only led to a discovery, it led to other discoveries through various scientists and scientific methods. All these men approached their experiments with different techniques; these techniques led them to countless discoveries of the atom, such as the proton, neutron, electron, atomic mass, atomic weight, and so on.



Think about your lessons in history and discuss how the time period that they lived in determined the outcome of their discovery/ or how it influenced those individuals to be the names that we know today.
As we go further and further into the past, we realize that these men did not have the technology that we have today. By not having the use of modern technology to their advantage, it is very easy to point out flaws in their experiments and theories. Although these men did not have the advantage we have today, we can conclude that they were very intellectual and thoughtful for their time period, leading them to new discoveries.


Why do we consider the atomic theory still a theory? What are the new developments?
The Atomic Theory still has yet to be proven, even though it has stood the test of time. New discoveries and add-ons have been made to this theory. Also, we have discovered a few flaws with this theory.




Why does it matter that we understand the structure of the atom?
Atoms are the basic building blocks off all matter. We must study the atom in order to understand their basic structure and why they exist. We are surrounded and even made up of atoms. By understanding the true nature of atoms, we can learn that they are more than just "random" particles.

The Atom

So we have been discussing the beginnings of the atom, and now I want to know what you think.

-who were the main characters in the development of the atom? Democritus,Aristotle, John Dalton, Joseph John Thomson, Robert Millikan, Max Planck, Ernest Rutherford, Niels Bohr, Louis deBroglie, Erwin Schrodinger, Werner Heisenberg, and James Chadwick.

- Why were they vital to the development of the atom? They made theories about matter and the atom and through time and experiments have contributed to the knowledge of the atom we have today.

_ what made them differnt if anything? These men were thinkers who sought answers to their own questions and theories, they wanted to learn and prove their claims.

- Think about your lessons in history and discuss how the time period that they lived in determined the outcome of their discovery/ or how it influenced those individuals to be the names that we know today (aka did it matter where they grew up or if they had money?)? Democritus is probably the only one of these scientist who had problems proving his theory because of the primitive technology in the ancient Greek era. The other scientists had more advanced technology and their discoveries helped the others that did research down the road.

- Why do we consider the atomic theory still a theory? What are the new developments- would love for you to share new sources here about what you find? The atomic theory is still growing and we are still finding new elements and studying the atoms. The advances we have made through the years have really given us an understanding of the atoms and elements, but we still need to keep learning more about them.

- Why does it matter that we understand the structure of the atom? Because the structure gives us an understanding of why it is the way it is. It also allows us to spot differences that may lead to new elements and theories on atoms.

Beginning of Chemistry

Main Characters in the Development of the Atom

Democritus

J.J. Thomson

Lord Ernest Rutherford

Robert Millikan

Niels Bohr

James Chadwick

Vital to the Development

Democritus is associated with the first atomic theory; to him atoms were completely solid, homogeneous, indestructible objects.

Joseph John Thomson discovered the electron in 1897 by experimenting with cathode rays. He also came up with the "plum-pudding" model of the atom, which suggested a solid atom with positively and negatively charged particles evenly distributed throughout the mass of the atom.

Ernest Rutherford discovered that most of the atom is made up of "empty space." In 1909 he conducted the "gold foil" experiment, from which he found that most of the atom's mass was concentrated in a minute nucleus. He concluded that the positively charged nucleus was surrounded by a great deal of "empty space" through which the electrons moved.

Robert Millikan found the mass of the electron to be 9.11x10^-28g by combining the results from his "oil-drop" experiment, which allowed him to measure the charge on an electron, with those of Thomson's.

Niels Bohr added the idea of fixed orbits, or energy levels for the electron traveling around the nucleus, to Rutherford's atomic model. This model allowed for the idea that electrons can become "excited" and move to higher energy levels for brief periods of time.

James Chadwick is known as the discoverer of the neutron. He found these uncharged particles with essentially the same mass as the proton.

What Made them Different

Each scientist was different mainly because of their approach on the atom. They each used different experiments and came out with different results. Even though they were each studying the atom, they each went above and beyond what the one before them studied. They also studied and discovered different parts of the atom such as the proton, neutron, and electron. All in all, each scientist helped with discovering the atom.

Time Period

If we look at the time line of the development of the atom, we notice that as we get closer to modern times, more and more discoveries are made. This is all due to advancements in technology. Also, the advancements in technology allowed the scientists to do further research on past experiments to answer some unanswered questions. This led to clarification and better understanding of the atom. Therefore we may think of the more modern scientists as better scientists but honestly, they had more to work with.

Atomic Theory

After hundreds of years of research, no one has yet seen a single atom. Some of the very best microscopes have produced images of groups of atoms, but no actual picture of an atom yet exists. Therefore, we can't be completely certain of the existence of atoms and of the models they have created for scientists. But. the models of the atom, like other scientific models, can be tested by experimentation. Those models that pass the test of experimentation survive, while those that do not are abandoned. The model of atoms that scientists use today have survived and have been modified by untold numbers of experiments and will be subjected to other such tests in the future. Since we have further testing to do, we can not call it a law yet.

Structure of an Atom

It's important to understand the structure of an atom because atoms are the basic building blocks of matter. They form the molecules that are involved in the processes of living systems. Through the reactions of different atoms, organisms exist. By developing an understanding of the atom and its components, we is develop an understanding of life.

Atom

-Who were the main characters in the development of the atom?
· 1803 - John Dalton
· 1830 - Michael Faraday
· 1869 - Johannes Hittorf
· 1879 - William Crookes
· 1897 - J.J. Thompson
· 1895 - William Conrad Roentgen
· 1899 - Ernst Rutherford
· 1908-1917 - Robert Millikan
· 1913 - A. van den Broek
· 1914 - H. G. J. Moseley
· 1932 - James Chadwick

- Why were they vital to the development of the atom?

· John Dalton – Atomic Theory
· Michael Faraday - Cathode - metal plate connected to the negative end. Anode - metal plate connected to the positive end.
· Johannes Hittorf - Found that when a solid object was placed between the cathode and anode, a shadow was cast on the end of the tube across from the cathode.
· William Crookes - Developed a better vacuum pump that allowed him to produce cathode-ray tubes with a smaller residual gas pressure.
· J.J. Thompson - Found that cathode rays could be deflected by an electric field, showed that cathode "rays" were actually particles, found the charge to mass ratio of the particles to be approximately 108 Coulomb (C) per gram, same charge to mass ratio regardless of metal used for cathode/anodeor gas used to fill the tube.
· William Conrad Roentgen - Discovered x-rays while using cathode-ray tubes. Found that x-rays could passthrough solid objects.
· Ernst Rutherford - Studied absorption of radioactivity.
· Robert Millikan – Oil-drop experiment.
· A. van den Broek - Suggested that the positive charge on atoms should be compared to their atomic numbers, not their atomic weights.
· H. G. J. Moseley - Studied the frequencies of the x-rays given off by cathode-ray tubes when electrons strike the anode. Found that there was a relationship between the frequencies (v) of the x-rays given off by the cathode-ray tube and the atomic number of the metal used to form the anode
· James Chadwick - Proved that neutrons, neutral particles in the nucleus that made up approximately half the mass of an atom, did exist.- Think about your lessons in history and discuss how the time period that they lived in determined the outcome of their discovery/ or how it influenced those individuals to be the names that we know today (aka did it matter where they grew up or if they had money?)

· Their money or background didn’t matter, of course it could have changed the way they looked at something, but they all had to have something in common to find the information that we have now.

- Why do we consider the atomic theory still a theory? What are the new developments- would love for you to share new sources here about what you find?

· The word "theory" in science doesn't mean a guess. It means an idea that has been very well confirmed and has stood the test of time. The same applies to biological evolution, which has stood the test of time even longer than relativity.
· The development of the atomic theory advanced greatly when chemistry became an exact science during the late 1700's. Chemists discovered that they could combine elements to form compounds only in certain fixed proportions according to mass. In 1803, a British chemist named John Dalton developed an atomic theory to explain this discovery. Dalton proposed that each element consists of a particular kind of atom and that the varying properties of the elements result from differences in their atoms. He further suggested that all atoms of a given element are identical in size, shape, and mass. According to Dalton's theory, when atoms combine and form a particular compound, they always combine in a specific numerical ratio. As a result, the composition by mass of a particular compound is always the same
- Why does it matter that we understand the structure of the atom?

· Because an atom is the basic unit of matter, so everything has atoms in it. We should know the structure, how they work, and what they contain because they forever surround us.

5th period Beginning of Chemistry Blog Response

Main Characters- John Dalton, J.J. Thomson, William Crookes, Michael Faraday, Robert Millikan, James Chadwick, Democritus.

Why were the vital to the developement to the atom- John Dalton was vital to the development of the atom because he came up with symbols to represent the atoms of the different elements, also he had an Atomic Theory and contributed to the atomic weight scale. J.J. Thomson was vital to the atom because he discovered electrons, he came up with the model called the "plum pudding"atomic model. He said that there must be positvely charged particles which must carry the mass of the atom. William Crookes was vital in the development of the atom because of his contribution to cathode ray research. He actually developed a better vacuum pump that allowed him to produce cathode-ray tubes with smaller residual gas pressure. Micheal Faraday was vital to the atom because of the cathode and anode. Robert Millikan was vital to the atom because he measure the charge of an electron with his oil drop apraratus. James Chadwick was vital to the atom because he discovered the neutron in the atom which later results in the atomic bomb. Democritus was vital in the discovery of the atom because he produced this particle and the Atomic Theory.

What made them different- The things that made them different were just all of their different personalities and thoughts. They are linked in the same sort of category, the atom, but they all just went about it in different ways. Some experimented and some just went with their gut.

Time period they lived in and the outcome of discovery- Money was definitely important in the way they discovered the atom. If they had money then they were able to use better technology. And yes it did matter when they grew up because of course the later they grew up there was more technology and more scientists that would discover things that would help with what they might be working on.

Why do we consider the atomic theory still a theory? What are the new developments?- it is still a theory because of the discovery of nuclear fusion/fission and radioactivity. Dalton was also incorrect saying that the atom was indivisible. We now know that atoms can be destroyed in nuclear reactions but not chemical reactions.

Why does it matter that we understand the structure of the atom?- It is important to know the structure of the atom because we need to know the world around us and they are all around us. They are the basic building blocks of matter so if you don't understand the structure of the atom then you can't get much into the discovery of anything else.

The Atom

Main Characters:

Democritus-He suggested that all matter has tiny particles and he called them Atoms

John Dalton- He came up with the Atomic Theory

JJ Thompson- He discovered electrons

Ernest Rutherford- This man discovered protons

James Chadwick-Discoverd neutrons

Why are they vital?
These men are vital to the devolpment of the atoms because it is because of them that we know so much about these tiny particles and understand more.

Why are they different?
These scientist are different because they experimented to prove what they thought.

Did it matter?
It did matter where they grew up and what time period they grew up in. The reason being is depending on when they grew technology could have helped them more. They didn't necessarily need to have a lot of money but it wouldn't have hurt. The more money they had could have them go even further with their experiments and prove more.

Atomic Theory
Its still a theory because it has not been proven and Dalton had been wrong on some things.

New Developments-The nucleus of the atom is being studied to see if we can come with sources of nucleur fission and fusion for energy

Why does it matter that we understand the structure of the atom?
The reason we need to understand the atom is because matter is all around us and all mater has atoms. If we understand what matter is made up of we can make life easier for us and become smarter about our surroundings.

-who were the main characters in the development of the atom?
400 BCE-Democritus 1909- Earnest Rutherford
1789- Antoine Lavasosier 1922- Niels Bohr
1803- John Dalton 1932- James Chadwick
1897- J.J. Thompson
- Why were they vital to the development of the atom
Democritus produced an Atomic Theory. Als0 the existance of an ultimate particle known as the atom. Lavoisier stated the 1st version or law of conservation of mass. Also the 1st extensive list of the elements. Dalton had an Atomic Theory. Also came up with a list of symbols to represent the atoms of the different elements. Also contributed to the atomic weight scale. Thompson had the "plum pudding" atomic model. It stated that the volume of the atom is composed primarily of the more massive positive portion ( the pudding) and the smaller electrons ( raisons in pudding) are dispersed throughout the positive mass to maintain charge neutrality.Rutherford proposed the nucleauer atom as a result of the gold-foil experiment. All the positive charge an all the mass of an atom occupied a small volume at the center of the atom and that most of the volume of the atom was empty space occupied by the electron. Bohr had the Bohr model or the " planetary model". However it was not accurate. He also helped with the understanding of the atomic structure. Chadwick discovered the neutron in the atom wich later led to the atomic bomb.
_ what made them different if anything
Thier minds and upbringing. They where all going for close to the same thing but just going at it different ways which made them all successful and well known for what they did. Their surroundings and education made them different but in the end they were all tyring to unerstand what an atom was.
- Think about your lessons in history and discuss how the time period that they lived in determined the outcome of their discovery/ or how it influenced those individuals to be the names that we know today (aka did it matter where they grew up or if they had money?)
Of course it matters if they had money or not. If they did then they were better able to get an education and have top noth supplies. Also they had different scientist inspiring them. Also each year other scientist were enventing newer stuff that could help them out in there research.
- Why do we consider the atomic theory still a theory? What are the new developments
The atomic theory is still a theory and not a law because it wasn't accurate. When Dalton said atoms where indivisible he wasn't correct.
- Why does it matter that we understand the structure of the atom
Because they are the basic building blocks of all matter. If we don't understand the atom then we can' t further are knowledge in much of anything.

Beginning of Chemistry

-who were the main characters in the development of the atom

John Dalton, J.J. Thomson, Ernst Rutherford.

- Why were they vital to the development of the atom
It is because of them that we know what an atom is and how it is made up

- what made them different if anything.
Some scientists made theories and never actually tried to prove them while other scientists experimented their theories.

- Think about your lessons in history and discuss how the time period that they lived in determined the outcome of their discovery/ or how it influenced those individuals to be the names that we know today (aka did it matter where they grew up or if they had money?)
Democritus is probably the only one of these scientist who had problems proving his theory because of the primitive technology in the ancient Greek era. The other scientists had more advanced technology and their discoveries helped the others that did research down the road.

- Why do we consider the atomic theory still a theory? What are the new developments- would love for you to share new sources here about what you find
Atomic theory is only a theory because parts of it have been proven false. Dalton claimed that atoms could not be split into smaller structures, but they are composed of protons, electrons, and neutrons.

- Why does it matter that we understand the structure of the atom

If we understand the structure of the atom we can determine how everything in the universe is constructed and how it interacts with each other.

beginning of chemistry

John Dalton formulated Atomic theory. Joseph John Thompson discovered the electron in 1897. James Chadwick discovered the neutron in 1932. Ernest Rutherford was the primary discoverer of the proton in 1918. Others are Democritus, Robert Millikan, Max Planck, Niels Bohr, and Louis deBroglie.

It is because of all the above scientists that we have the all our present knowledge of the atom. The scientists developed their own theories and thirsted for knowledge. . . . . ?

All of the listed scientists, but especially the ones from earlier time periods, must be given credit for making their discoveries and theories in times with very limited technology and previous knowledge.



Atomic theory is only a theory because parts of it have been proven false. Dalton claimed that atoms could not be split into smaller structures, but they are composed of protons, electrons, and neutrons. Also, no one can be sure that atoms even exist, because no microscope can enlarge something so small to be visible to us.



It matters that we understand the structure of the atom so we can determine how everything in the universe is constructed and how it interacts.

5th Period Beginning of Chemistry Blog Response

Main Characters- John Dalton, Michael Faraday, Johannes Hittorf, William Crookes, J.J. Thompson, William Roentgen, Esnst Rutherford, Robert Millikan, A. van den Broek, H.G.J. Moseley, James Chadwick

Vital to the Development-

Dalton- Atomic Theory

Faraday- cathode and anode

Hittorf- Found that when a solid object was placed between the cathode and anode, a shadow was cast on the end of the tube across from the cathode.

Crookes-Developed a better vacuum pump that allowed him to produce cathode-ray tubes with a smaller residual gas pressure.

Thompson-There must be positively chargedparticles which also must carry the mass of theatom. Dalton's model is now incorrect becauseatoms are divisible.

Roentgen- Discovered x-rays while using cathode-ray tubes. Found that x-rays could passthrough solid objects.

Rutherford-Studied absorption of radioactivity.

Millikan- measured the charge on an electron with his oil-drop apparatus

Broek- Suggested that the positive charge on atoms should be compared to their atomic numbers, not their atomic weights.

Moseley-Found that there was a relationship between the frequencies (v) of the x-rays given off by the cathode-ray tube and the atomic number of the metal used to form the anode:

Chadwick- Proved that neutrons, neutral particles in the nucleus that made up approximatelyhalf the mass of an atom, did exist.



What made them different-

All these scientists were very different. Although they were ultimetly studying the same general thing their studies were very specific. However, each study contributed to the bigger picture of learning more about the atom.



Time Period They Lived in Determined Outcome-

Obviously the technology of the time was not even close to advanced as it is in the twenty-first century. During the 1930s things such as parking meters, regular television service, and radio telescopes were being discovered. Therefore this hindered the scientists abilites to discover new things. Which makes their discoveries that much more impressive.



Why is the atomic theory still a theory? New Developments?

Unexplained chemical phenomena was quickly explained by Dalton with his theory. Dalton's theory quickly became the theoretical foundation in chemistry.

It is still a theory because the discovery of nuclear fusion/fission and radioactivity prompted revision of point #2. Isotopes prove that atoms of the same element can actually have small differences due to a different number of neutrons. Also, the existence of ions with varying numbers of electrons also contradicts this point

Modern atomic theory is a little more involved than Dalton's theory but the essence of Dalton's theory remains valid. Today we know that atoms can be destroyed via nuclear reactions but not by chemical reactions. Also, there are different kinds of atoms (differing by their masses) within an element that are known as "isotopes", but isotopes of an element have the same chemical property.

Why does it matter that we understand the structure of the atom?

It matters because atoms are all around us. Therefore, to understand our natural world and the things around us we need to know how an atom works. The basic idea of the atom is atomic structure. If you do not know atomic structure then it is difficult to really study what the atom is.

beginning of chemistry

So we have been discussing the beginnings of the atom, and now I want to know what you think.

-who were the main characters in the development of the atom

- Why were they vital to the development of the atom

_ what made them differnt if anything

- Think about your lessons in history and discuss how the time period that they lived in determined the outcome of their discovery/ or how it influenced those individuals to be the names that we know today (aka did it matter where they grew up or if they had money?)

- Why do we consider the atomic theory still a theory? What are the new developments- would love for you to share new sources here about what you find

- Why does it matter that we understand the structure of the atom


Hey ya'll you have to post your thoughts, then you have to respond to a post from one of your classmates!

Due Date? Week of 9/20-9/24 depending on the day Chemistry sets- that includes your post and and a response to a classmate