Matter
Anything that takes up space and has mass
Compound
A substance consisting of two or more elements in a fixed ratio
Element
A substance that cannot be broken down into other substances by chemical reactions
Atom
The smallest unit of matter that still retains the properties of an element
Neurons
A subatomic particle that has no electrical charge
Protons
A subatomic particle that has a positive electrical charge
Electrons
A subatomic particle that has a negative electrical charge
Atomic number
Number of protons in an element’s ucleus
Mass number
The sum of protons and neutrons in an element’s nucleus
Isotopes
Two atoms of an element that differ in the number of neutrons
Atomic mass
The atom’s total mass
Radioactive isotopes
Isotopes that decay spontaneously, giving off particles and energy
Half-life isotope
“parent” isotope that decays into it’s “daughter” isotope at a fixed rate
Radiometric dating
The measure of the ratio of different isotopesand calculating how many half-lives have passed since the fossil or rock was formed
Energy
The capacity to do work or cause change
Potential energy
Energy that matter possesses because of its location or structure
Valence electrons
Electrons that are located in the outermost shell (valence shell)
Orbital
A 3D space where an electron is found 90% of thetime
Covalent bond
The sharing of a pair of valence electrons by two atoms
Molecule
Two or more atoms held together by covalent bonds
Single bond
The sharing of one pair of valence electrons between two atoms
Double bond
The sharing of two pairs of valence electrons between two atoms
Valence
An atom’s bonding capacity
Electronegativity
An atom’s attraction in a covalent bond (pulling more electrons towards itself)
