- In modern periodic table, the elements are arranged in ascending order of proton number.
- The vertical columns of the periodic table is called GROUPs whereas the horizontal rows is called the PERIODs.
- The vertical columns of the periodic table are called Group.
- There are 18 groups in the periodic table.
- All the elements in the same group have same number of valence electron.
- Thus, elements in the same group exhibit similar chemical properties.
- The Group is named according to their position in the periodic table. For example, the first group is called Group 1, the second group is called Group 2 and so on.
- Group 3 to Group 12 are categorised to another big group, called the Transition Metal Group.
- Group 1, 2, 17 and 18 have trivial name, as shown in the table below.
|Group 1||The Alkali Metals|
|Group 2||The Earth Alkaline Metals|
|Group 17||The Halogens|
|Group 18||The Noble Gases|
- The horizontal rows is called the PERIOD.
- There are 7 periods in period table.
- The first period only has 2 elements only.
- The second and third period consist of 8 elements, are called the short period.
- The forth and the fifth period consist of 18 elements, are called the long period.
- The sixth and the seventh period has 32 elements.