Atoms and the Periodic Table

The periodic table shows all the [blank_start]elements[blank_end] that have been discovered.

There are about [blank_start]100[blank_end] known elements.

There are 2 types of element: [blank_start]metal[blank_end] and [blank_start]non-metal[blank_end]

Metals are found on the [blank_start]left[blank_end] of the periodic table.

Non-metals are found on the [blank_start]right[blank_end].

Each element has a unique number called the [blank_start]atomic[blank_end] number.