Chemistry Test Vocab

y; the outcome. Then “then”

An explanation that is based on prior scientific research or observations and that can be tested

x; causes the outcome. The “if”

Anything that has mass and takes up space

A property of matter that describes a substance’s ability to participate in chemical reactions Ex: flammable? Soluble?

A change that occurs when one or more substances change into entirely new substances with different properties Ex: catching on fire, two chemicals reacting,

A characteristic of a substance that can be observed without involving a chemical change Ex: color, luster, density, color, hardness

A change of matter from one form to another without a change in chemical properties

The smallest unit of an element that maintains the properties of that element

The number of protons in the nucleus of an atom; the atomic number is the same for all atoms of an element

An atom that has the same number of protons (or the same atomic number) as other atoms of the same element do but that has a different number of neutrons (and thus a different mass); atoms the same element, but different mass

The sum of the number of protons and neutrons in the nucleus of an atom

Negative Very small Electron cloud

Negative Tiny Outermost shell of atom (determines the atom’s chemical properties)

Positive 1 amu Nucleus

No charge 1 amu Nucleus

A form of matter that doesn’t have a definite volume or shape

The state of matter that has a definite volume but not a definite shape

The state of matter in which the volume and shape of a substance are fixed

A nonsolid state of matter in which the atoms are free to move past each other

The conversion of a liquid to a vapor when the vapor pressure of the liquid equals atmospheric pressure

Liquid to solid

Solid to liquid

Gas to liquid