Francium is the rarest element on Earth. Fr - atomic number 87

Tungsten is the hardest metal known to man. It is used for heavy-duty industries such as space travel.
W - atomic number 74

​also known as Wolfram

​Science Fun Fact

​Atomic - means pertaining to atoms
Mass - Latin massa - meaning material or matter

This number is used to calculate the number of neutrons in an atom.

​​Atomic Mass

​Atomic - means pertaining to atoms

This number represents the number of protons in the nucleus of the atom. It is UNIQUE!

Atomic Number

​It comes from Latin elementum - meaning the most basic form or rudiment.

An element cannot be broken down into simpler substances.

​​Element

​VOCABULARY

Matter makes up EVERYTHING

The atomic number is usually located in the top left corner of the box.
Example: 20

Atomic Number

​The atomic mass is the number usually at the bottom of the box.

Example: 40

Atomic Mass

Parts of an Atom

Look at the Atomic Number and that is the number of protons. The number of protons NEVER changes.
P = 19

​​Protons

There are the same number of electrons as protons in a neutral elemental atom.
E = 19

Electrons

To determine the number of neutrons, take the atomic mass and subtract the atomic number
39 - 19 = 20 Neutrons

Neutrons