Chemistry Final Review

Front

What type of reaction is characterized by the combination of substances to release energy, often in the form of heat and light?

Back

Combustion

Front

What are the subscripts in the chemical formula of a compound that indicate the number of atoms of each element present?

Back

Subscripts are numbers written at the lower right of an element symbol in a chemical formula.

Front

Identify the following: H, H₂, NaCl, Cl, O₂ in terms of molecule, compound, or element.

Back

H: element, H₂: molecule, NaCl: compound, Cl: element, O₂: molecule.

Front

What happens to the energy of a system during an endothermic reaction?

Back

The system is gaining energy.

Front

What is the central part of an atom that contains protons and neutrons?

Back

Nucleus.

Front

Define a molecule.

Back

A molecule is a group of two or more atoms bonded together.

Front

What is a compound?

Back

A compound is a substance formed when two or more different elements are chemically bonded together.

Front

What is the difference between an element and a compound?

Back

An element is a pure substance made of only one type of atom, while a compound is made of two or more different types of atoms chemically bonded.

Front

What is the law of conservation of mass?

Back

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

Front

What is an exothermic reaction?

Back

An exothermic reaction is a chemical reaction that releases energy, usually in the form of heat.