Big Bang and Atomic Theory

What are the five main ideas of Dalton's theory?

1. The five main ideas of Dalton's theory are all elements are made of atoms. 2. Atoms of a specific element are identical to others unlike atoms of different elements. 3. Atoms cannot be created or destroyed. 4. Atoms come together in ratios to form chemical compounds. 5. In chemical reactions atoms combine, separate, and rearrange themselves.

Niels Bohr, who worked with Rutherford, made some major contributions that affected what we know about the location of a particular part of the atom. Describe what Bohr changed about what we know about this part of the atom.

Bohr was able to discover and change what we know about the position of electrons in an atom. It isn't a gravitational pull that holds the electron but it is an electric force. The electron can jump from lower orbits and higher orbits with the necessary energy.

What part of the atom did Chadwick discover? Describe the particle

Chadwick discovered that the neutron was also part of the atom. The neutron is a subatomic particle that is in the nucleus of atoms. It is called a neutron because it has no charge. It is neutral.

Describe each parts' charge, location and relative mass

I finished the tutorial and was able to learn that the proton is found in the center of the atom (nucleus). Protons have a +1 charge and have a mass of about 1 amu. Another part of the atom is the neutron. The neutron is also found in the center of the atom (nucleus). They do not have any charge and they have about the same mass as protons. The last part of the atom is the electron. Electrons have a -1 charge and have a mass of .0005 amu.

What actually happened in Rutherford's experiment? What surprised Rutherford about the results?

In Rutherford's experiment, the particles went through the foil with no deflection or only a little deflection. Sometimes the particles would make a large angle deflection onto the detecting screen. The particles would even come back to their source. This surprised Rutherford because he was able to realize that Thomson was wrong that the atom was only positive. Rutherford found that it also had a negative charge.

What did Rutherford expect to happen?

In his experiment, Rutherford expected the particles to travel through the gold foil with little to no deflection.

Describe in your own words the basis for Dalton's theory.

In my own words, the basis for Dalton's theory is the matter cannot be created or destroyed and the composition of compounds will always have the same proportion of elements.

What did J.J. Thomson discover about the atom?

J.J. Thompson discovered that the atom is partly made up of electrons.

What was Thomson's atomic model called? Draw a sketch of Thomson's atomic model.

J.J. Thomson's atomic model was called the "Plum Pudding Model."

What are two pieces of evidence that support the big bang theory?

Red Shift: galaxies still expanding cosmic microwave background radiation abundance of different elements in the universe

What part of the atom did Rutherford discover?

Rutherford was able to discover the nucleus and proton as part of the atom.

How did Rutherford's experiment disprove Thomson's model of the atom?

Rutherford's experiment disproved Thomson's model of the atom by showing that there was another element in the center of the atom (nucleus) which is then surrounded by electrons.

Describe Rutherford's experiment.

Rutherford's experiment was testing to see if particles from a particle emitter would travel through gold foil and onto a detecting screen. He wanted to test the way these particles traveled and how they would react when they came into contact with the metal.

What are the three major parts in an atom?

The three major parts in the atom are the proton, neutron, and electron. The proton and neutrons are major contributors to the mass of the atom.

What did Thomson conclude and how did Thomson's findings revise Dalton's Atomic Theory?

Thomson concluded that electrons were a smaller unit than atoms and that atoms were divisible. This revised Dalton's Atomic Theory by saying that the atom wasn't the smallest unit of matter and it could be split.

How did Thomson use the cathode ray tube in his research?

Thomson positioning coils in his cathode ray tube in order to balance the forces and deflect the cathode rays. This proved that the rays were made of negatively charged particles.

Describe Thomson's model of the atom. What is wrong with the picture presented on the www.iun.edu page of Thomson's model?

Thomson's model of an atom is a circle with lots of little dots. The circle is a positive charged sphere and the little dots in it are electrons. The picture on www.iun.edu page is wrong because the negative and positives are in the wrong spots.

what part of atom is responsible for reactivity

electron

If an atom is neutral it will have same number of what and what

electrons and protons

What holds together the protons in the nucleus.

neutrons

What part of atom determines what element an atom will be? (Atomic number) They are also heavier pieces of the atom and they create identity of atom.

proton