A substance that cannot be broken down into simpler substances is an:

A change does not alter the chemical composition of a substance.

A change results in the formation of one or more new substances.

The law of of mass states that mass is neither created nor destroyed in a chemical reaction.

Boiling, melting, and are examples of physical changes.

The three main states of matter are solid, , and gas.

In a , the particles are packed tightly and vibrate in place.

The temperature at which a liquid becomes a gas is the point.

The phase change from a liquid to a solid is called:

The center of the atom is called the:

Protons have a charge.

Neutrons are found in the nucleus and have a charge.

Electrons are located in the electron surrounding the nucleus.

The number of protons in an atom is its number.

Atoms of the same element with different numbers of neutrons are called:

The total number of protons and neutrons in an atom is its number.

The negatively charged subatomic particles are called:

A chemical bond formed by the transfer of electrons is called an bond.

A bond formed by sharing electrons is bond.

The vertical columns on the periodic table are called or families.

The horizontal rows on the periodic table are called:

Elements in the same group have similar chemical .

Group elements are known as the alkali metals and react violently in water.

Group elements are called the halogens and are reactive nonmetals.

Elements on the left side of the periodic table are generally:

Elements on the staircase line between metals and nonmetals are called:

Elements on the right side of the periodic table are generally:

The metals in the middle of the periodic table that can form multiple ionic charges are called metals.

Ionic bonds usually occur between:

The study of the quantitative relationships in chemical reactions is called:

A chemical equation is required to perform calculations involving quantitative amounts of reactants and products.

The coefficients in a balanced equation represent the ratio of the reactants and products.

One mole of any substance contains 6.022 × 10^23 molecules, or ions (Avogadro’s number).

The mass of one mole of a substance is called its mass.

The reactant is the reactant that remains after the reaction is complete.

Covalent bonds usually occur between:

A is formed when two or more atoms are covalently bonded.

The smallest unit of an is called a formula unit.

In a covalent bond, electrons are shared unequally.

A positively charged ion is called a:

A negatively charged ion is called a:

Oyster die-offs started occurring in in the Northwest Pacific.

We looked at data for pollution, temperature, levels, and acidity.

Research shows that the ocean water was responsible for deformed oyster shells, causing the die-offs.

The -scale problems are low pH ocean water in the Northwest Pacific and CO₂ levels in the air.

An is a substance that donates H⁺ ions in solution.

A is a substance that donates hydroxide ions (OH⁻) or accepts H⁺ in solution.

The scale measures the acidity or basicity of a solution.

A solution with a pH than 7 is considered an acid.

A solution with a pH than 7 is considered a base.

A solution with a pH of 7 is considered:

The reaction between an acid and a base is a reaction.

In a neutralization reaction, an acid reacts with a base to produce a and water.

The energy stored in chemical bonds is known as chemical energy.

A reaction that absorbs heat is called:

A reaction that releases heat is called:

The process by which an unstable atomic nucleus loses energy is called decay.