A substance that cannot be broken down into simpler substances by chemical means.

The smallest particle of a substance that has all of the physical and chemical properties of that substance. They are made up of one or more atoms.

What is a substance that is made up of two or more elements that are chemically combined?

The number written before a chemical formula that denotes how many molecules are needed to balance an equation? This is the variable that can be changed when balancing chemical equations.

The index that denotes the number of atoms of an element in a chemical formula? This can not be changed when balancing chemical equations.

At what temperature does a substance change from liquid to gas?

What is the process of a gas turning into a liquid?

A property of a substance that can only be observed during the formation of a new substance.

What is the term for the number of protons in the nucleus of an atom?

What is the term for the number of protons plus neutrons in an atom?

A subatomic particle that moves outside the nucleus and has a negative charge. These particles do not contribute to the atomic mass of an atom.

The process in which a substance changes from the liquid state to the gaseous state.

The breaking or forming of bonds between molecules or atoms, making at least one new substance.

A change in a substance that does not involve the forming of a new substance.

A written expression that shows a chemical change, including the reactants and products.

A written expression that shows the elements in a chemical compound.

A one or two letter designation of an element.

The processes by which chemicals interact to form new chemicals with different compositions.

A substance's mass per unit of volume or the amount of space an object or substance takes up (its volume) in relation to the amount of matter in that object or substance (its mass).

A subatomic particle that exists inside the nucleus and has a positive charge.

A subatomic particle that exists inside the nucleus and has no charge.

Elements that are in the same column of the periodic table have the same number of valence electrons, these elements are in the same _______.

Elements that are in the same row of the periodic table have the same number of electron shells, these elements are in the same _______.

What is the difference between a homogenous mixture and a heterogeneous mixture?

Elements that form positive ions by losing electrons during chemical reactions and are typically hard, shiny materials with good thermal and electrical conductivity. They are found on the left side of the periodic table.

Elements that form negative ions by losing electrons during chemical reactions are brittle and poor conductors of heat and electricity. They are found on the right side of the periodic table.

Elements that are the middle ground between metals and nonmetals, exhibiting qualities of both groups of elements.

A solid formed by a change in a solution, often due to a chemical reaction or change in temperature that decreases solubility of a solid.

A substance that is present at the end of a chemical reaction.

A chemical substance that is present at the start of a chemical reaction, and is changed as the chemical reaction proceeds.

The measure of how readily a substance undergoes a chemical reaction.

An element or compound made up of one type of particle that have a fixed structure with definite properties.

A measure of how easily a substance can be ignited or burn.

The reason that the mass of the product must equal the mass of the reactants.

A property of a substance that can be observed without changing the substance?

The subatomic particle that is in the nucleus, has a positive charge and determines the atomic number of the element.

The subatomic particle that exists in the nucleus does not have a charge and determines an element's isotopes.

The subatomic particle that has a negative charge, exists outside the nucleus and determines when an atom becomes an ion (determines the charge of an atom).

These electrons exist in the outer energy level of an atom and determine how the elements reacts with other elements.