C1: Atomic Theory Flashcards
What is the defenition of an element?
A substance made up of only one type of atom
What are the two elements in the nucleus of an atom?
Protons and neutrons
What is the name of the rings that electrons sit in?
Energy levels (shells)
Who were the main 5 people who contributed to the current model of the atom?
John Dalton, John-Jacob Berzelius, Joseph John Thomson, Ernest Rutherford, Niels Bohr.
What was the plumb pudding model?
A model of the atom made by Joseph John Thomson, it had a circular ball with positive matter and Electrons floating around inside it.
What was the Gold Foil experiment?
An experiment carried out by Ernest Rutherford, he shot infered lazers (alpha particles) at a peice of gold foil. Most lazers went through the foil but some bounced off in different directions. This showed that although most of the atom is empty space there must be some sort of dense concentrated block in the middle of the atom.
Who was the first person to say that electrons were in shells (energy levels)?
Neils Bohr
Why do atoms have no overall charge?
Because they have the same amount of protons as electrons
What is an ion?
An ion is an atom without a neutral charge, this is because the number electrons has been lowered or increased, meaning the atom no longer has the same amount of protons as electrons
What is an isotope?
Atoms of the same element with the same number of protons but a different number of neutrons in the nucleus
What is the maximum amount of electrons in the first shell (energy level)?
2
What is the maximum amount of electrons in the 2nd and above shell (energy level)?
8
What did John Dalton discover about the atom?
- He was the first person to use the word ATOM
- He realised that different elements have different masses
- Thought atoms were solid shapes with no empty spaces
What did John Jacob Berzelius discover about the atom?
- Discovered that atoms were in circular shapes
- He took the first letter of the Latin Names of each of the elements and made those their chemical symbols, some of these symbols are still used in todays periodic table
What did Joseph John Thomson discover about the atom?
- Created the plumb pudding model, in which electrons were sat in a positive matter
- Figured out the mass of an electron was 1/2000 of the mass of Hydrogen
What did Ernest Rutherford discover about the atom?
- Carried out the gold foil experiment, in which alpha particles were fired at a thin sheet of gold.
- Discovered that there was a small dense area in the middle of the atom (now known as the nucleus)
- Discovered that most of the atom is empty space
- Discovered that the atom is neutral
- Discovered that the nucleus had a positive charge
- Put electons on energy levels that did not orbit the nucleus but instead were in oval shapes
What did Niels Bohr discover about the atom?
- Discovered that the mass of the atom is in the central nucleus
- First person to say that electrons are in shells/energy levels orbiting the nucleus
- Said that electrons with full outer shells are not very reactive
- Realised electrons control the reactivity of the atom
Who carried out the gold foil experiment?
Ernest Rutherford
What is a metallic bond?
A bond between two metals
What is a covalent bond?
A bond between two non-metals
What is an ionic bond?
A bond between a metal and a non-metal
What is nanoscience?
The study of structures between 1-100 nanometers (nm)
