Metals and Non-Metals
Elements are categorized by their chemical and physical properties using the periodic table.
The periodic table is an arrangement of elements according to their increasing atomic numbers.
Elements with the same chemical properties are placed in vertical columns (groups) horizontal rows (Period).
Periodic table was made by a Roman scientist called Dmitri Mendeleev in 1869. He arranged the elements in order of mass and left spaces for other elements that had not been discovered yet.
| 0:0 | Group 1 | Group 2 | Group 3 | Group 4 | Group 5 | Group 6 | Group 7 | Group 8 |
|---|---|---|---|---|---|---|---|---|
| Period 1 | 1H | 2He | ||||||
| Period 2 | 3Li | 4Be | 5B | 6C | 7N | 8O | 9F | 10Ne |
| Period 3 | 11Na | 12Mg | 13Al | 14Si | 15P | 16S | 17Ci | 18Ar |
| Period 4 | 19K | 20Ca |
On the periodic table, the atomic numbers increases from left to right. The elements in the first twenty elements are classified as metals, semi-metals and non-metals from left to right.