Atomic Theory
Who discovered the nucleus?
Rutherford
What are the subatomic particles found in the nucleus?
Protons and Neutrons
What state is an atom in when it's at it's lowest possible energies?
Ground State
An elements atomic number is tied directly to the number of this subatomic particle.
Protons
Calcium's atomic number is 20, how many protons does it have?
20
Rutherford’s gold foil experiment provided evidence that nucleus has what charge?
Positive
What is the negatively charged subatomic particle located outside of the nucleus?
electrons
What state is an electron in as it moves to a higher energy level?
Excited State
What is the formula for finding the atomic mass of an element?
Atomic Number + Number of Neutrons = Mass Number
All oxygen atoms have 8 protons, how many neutrons are in an atom of Oxygen-18?
10
Democritus named the smallest particles this, because they could not be divided.
Atoms
What is the dense, positively charged mass at the center of an atom?
Nucleus
What is happening when an electron moves to a lower energy level?
The electron is emitting energy
What is the maximum number of electrons that can occupy an atomic orbital?
2
If 2 grams of element X combine with 4 grams of element Y to form compound XY, how many grams of element Y would combine with 12 grams of X to form the same?
6 grams
JJ Thomson's experiment provided the first evidence of this.
Subatomic Particles
What is the maximum number of electrons that can occupy an atomic orbital?
2
What evidence do scientists have that electrons move from one energy level to another?
They can measure the energy gained and lost by electrons.
How do Isotopes of an element differ?
Number of the neutrons in the atom.
An atom has an energy level of 2, how many orbitals does it have?
4
What did Bohr introduce to the atomic theory with his model?
Electrons moving in orbits around the nucleus.
What happens to an electron in an atom when the atom gains or loses energy?
The electron can move from one energy level to another.
What is the difference between Bohr's model of the atom and the modern atomic theory?
The Electron Cloud
If an atom has an energy level of 4 how many orbitals does it has?
16
If an atom has an energy level of 4, what is the maximum number of electrons it could hold?
32 electrons