Grade 8 - Atom, Molecules and Elements

Front

What is an elemental molecule?

Back

An elemental molecule is a molecule that consists of two or more atoms of the same element bonded together, such as O2 (oxygen) or N2 (nitrogen).

Front

What is a compound molecule?

Back

A compound molecule is a molecule that consists of two or more different elements bonded together, such as H2O (water) or CO2 (carbon dioxide).

Front

What does atomic mass represent?

Back

Atomic mass is the weighted average mass of an atom's isotopes, measured in atomic mass units (amu). It reflects the number of protons and neutrons in the nucleus.

Front

What is the symbol for Hydrogen?

Back

The symbol for Hydrogen is H.

Front

What is the atomic number of an element?

Back

The atomic number is the number of protons in the nucleus of an atom, which determines the element's identity.

Front

What is the symbol for Krypton?

Back

The symbol for Krypton is Kr.

Front

What is the atomic mass of Oxygen (O)?

Back

The atomic mass of Oxygen is approximately 16 amu.

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 together.

Front

What is the formula for water?

Back

The formula for water is H2O.

Front

What does the subscript in a chemical formula represent?

Back

The subscript in a chemical formula indicates the number of atoms of the element present in the molecule.