Unit 2 Chemistry Test

Chemical Change

atoms rearranged in a chemical reaction, has new properties

isotope

version of an element with more/less n⁰ than period table

half life

amount of time for radioactive isotope to decay by half

alpha decay

least dangerous decay, Helium is daughter nucleus

Beta decay

Decay where mass number is same but protons change

Fundamental Force

Force preventing nucleus from exploding despite protons

Gamma Decay

Most dangerous decay, high energy, hardest to stop

Indivisible

Dalton thought atoms were this, but protons, neutrons, and electrons exist

Physical change

No identity change, maybe a phase change

Nuclear decay

Aka Radioactive decay

Thomson

Discovered electrons, plum pudding model

Chadwick

Discovered neutrons

Schrödinger

Used math to describe electron behavior, electron cloud

Rutherford

Discovered protons & dense nucleus, nuclear model

Dalton

First to describe modern atomic theory, Billard model

Faraday

First Bunsen burner & admired by Albert Einstein

Bohr

Planetary model, first to state electrons are in orbitals

Mosley

Credited with modern periodic table; organized by protons numbers

Democritus

Greek philosopher, first to describe “atomos” as sphere

Alchemists

Added to chem knowledge: procedures & glassware

Equation to determine number of neutrons in an atom

Mass number minus Atomic number

How do you determine a ground state elements mass number?

Round the atomic mass to the nearest whole number

Equation for finding the average atomic mass using abundance percentage

(Mass number X Abundance)(Mass number X Abundance)/Total Abundance