physical and chemical changes

Front

What is the definition of atomic mass?

Back

Atomic mass is the mass of an atom, typically expressed in atomic mass units (amu), which reflects the total number of protons and neutrons in the nucleus.

Front

What is a physical change?

Back

A physical change is a change that affects one or more physical properties of a substance without altering its chemical composition.

Front

What is a chemical change?

Back

A chemical change is a change that results in the formation of new chemical substances, involving the breaking and forming of bonds.

Front

Give an example of a physical change.

Back

Melting ice is an example of a physical change.

Front

Give an example of a chemical change.

Back

Baking bread is an example of a chemical change.

Front

What is the role of protons in an atom?

Back

Protons are positively charged particles found in the nucleus of an atom and determine the atomic number and identity of the element.

Front

What is the relationship between protons and electrons in a neutral atom?

Back

In a neutral atom, the number of protons equals the number of electrons.

Front

What is the definition of an element?

Back

An element is a pure substance that cannot be broken down into simpler substances by chemical means and is made up of only one type of atom.

Front

What is the definition of a compound?

Back

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

Front

What happens during a combustion reaction?

Back

During a combustion reaction, a substance reacts with oxygen, releasing energy in the form of heat and light, often producing carbon dioxide and water.