What everything around you is made of.

An educated guess or proposed explanation for an occurrence that will undergo further investigation and testing.

The measurement of something from end to end.

The measurement of how much space an object occupies.

The heaviness of an object, dependent upon the force of gravity pulling down on it.

How much matter something has.

The building blocks of matter.

A specific type of atom.

A substance formed from the joining of two or more atoms.

A substance that is made of atoms or molecules which cannot be broken down without changing it into something else.

A lasting attraction between atoms that forms a molecule or a chemical compound.

A characteristic of a substance that can be observed without changing its chemical makeup.

A characteristic of a substance that can only be observed through a chemical change.

How well a substance will dissolve into another substance.

How compact a solid, liquid, or gas is; it equals mass divided by volume.

The central part of an atom that contains neutrons and protons.

A positively charged particle found in the nucleus of an atom.

A particle with no charge found in the nucleus of an atom.

A negatively charged particle found in the area surrounding the nucleus of an atom.

The number of protons of an element that identifies the element and determines its place on the periodic table.

The weight of the number of protons plus the number of neutrons of an atom.

A different form of an element that has the same number of protons but a different number of neutrons.

An atom that has either lost or gained electrons, giving it an overall positive or negative charge.

When atoms form chemical bonds, they want to fill each of their electron shells to a total of eight electrons to be stable.

A chemical bond formed between atoms when one atom loses electrons and the other atom gains electrons, forming a positively or negatively charged ion.

A chemical bond formed when atoms share electrons, fulfilling the octet rule and achieving stability.

Matter cannot be created nor destroyed; in a chemical reaction, the total mass of the reactants will equal the total mass of the products.