All the different elements are arranged in a chart called the
periodic table.
Here are the main features of the table:
The horizontal rows are called
periods.
The vertical columns are called
groups.
Elements in the same group are similar to each other.
The
metals are on the left and the
non-metals are on the right (hydrogen is a non-metal but is often put in the middle).
The main groups are numbered from 1 to 7 going from left to right, and the last group on the right is Group 0.
The block in between Group 2 and Group 3 is where the
transition metals are placed.
There are only two elements in Period 1 (hydrogen and helium).