Scientists
Argued that all matter was made from indivisible particles
Who is Democritus?
Contain different numbers of neutrons.
What are the nuclei of isotopes?
Electrons that are in the highest energy level.
What is a valence electron?
Columns in the periodic table.
What are groups?
Matter cannot be created or destroyed, but matter can change forms?
What is the Law of conservation of Mass?
Credited with the first version of the Periodic Table
Who is Mendeleev?
Same as the number of protons.
What is the number of electrons?
Has more energy than an atom in a ground state.
What is an atom in an excited state?
An alkali metal that is part of table salt.
What is Sodium?
The state of matter that has definite volume but not a definite shape.
What is a liquid?
This experiment demonstrated that a dense mass with a concentrated positive charge was located at the center of the atom.
Unique to each element
What is the number of protons?
Has only one orbital
What is the lowest energy level?
A halogen that is part of the compound table salt.
What is Chlorine?
What is the number of valence electrons?
Did not yet know of subatomic particles when he developed his theory.
Who is Dalton?
Has a negative charge.
What is an electron?
What is an electron cloud?
Rows in a periodic table.
What are periods?
The state of matter which has no definite volume and no definite shape.
What is a gas?
This experiment showed that all matter has negatively charged particles which is why the glowing beam was attracted to the positive plate.
What is Thomson's Experiment?
The number of protons plus the number of neutrons.
What is the atomic number?
Contain a maximum of two electrons.
What are orbitals?
The group of elements that are most reactive.
What are Group 1A elements?
In this nuclear model the positive charge is concentrated in the center of the atom.
What is Rutherford's nuclear model?