Chemistry Unit 2

Schrodinger

Found that electrons don’t move around the nucleus in orbits, but exist in specific energy levels as a cloud.

Dalton

Theory stated that matter is created from atoms which are small and indivisible, elements can combine and form compounds, and that all atoms of a given element are identical

Rutherford

Discovered the nucleus of an atom and that an atom is mostly empty space using a gold foil experiment

Bohr

Believed electrons orbited the nucleus in definite paths

Thomson

Theory stated that atoms have no charge and are made out of spheres of positive charges with negatively charged electrons embedded in them

Anion

A negatively charged ion formed when an atom gains electrons.

Cation

A positively charged ion formed when an atom loses one or more electrons.

Ion

A charged particle that results from the loss or gain of electrons by an atom or molecule.

Isotope

Different # of neutrons

What order do the nuclear emissions go in from least to greatest?

Alpha, Beta, Gamma

What is the atomic #?

Total # of protons

What does the atomic mass represent?

Total number of protons and neutrons in an atom's nucleus.

Which nuclear decay consists of only energy?

Gamma

How do the masses of protons, neutrons, and electrons compare? 

Proton:1

Neutron:1

Electron:0

What is the charge of an atom?

Neutral

What is a half-life?

The amount of time it takes for half of a radioactive substance to decay.

Is the half-life of a substance affected by heat?

No

# of orbitals in s, p, d, f

1, 3, 5, 7

# of electrons

2, 6, 10, 14

Why do elements form ions?

To achieve stable electron configurations