Modern Periodic Table

  1. In modern periodic table, the elements are arranged in ascending order of proton number.
  2. The vertical columns of the periodic table is called GROUPs whereas the horizontal rows is called the PERIODs.

Group

  1. The vertical columns of the periodic table are called Group.
  2. There are 18 groups in the periodic table.
  3. All the elements in the same group have same number of valence electron.
  4. Thus, elements in the same group exhibit similar chemical properties.
  5. 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.
  6. Group 3 to Group 12 are categorised to another big group, called the Transition Metal Group.
  7. Group 1, 2, 17 and 18 have trivial name, as shown in the table below.
Group Trivial Name
Group 1 The Alkali Metals
Group 2 The Earth Alkaline Metals
Group 17 The Halogens
Group 18 The Noble Gases

Period

  1. The horizontal rows is called the PERIOD.
  2. There are 7 periods in period table.
  3. The first period only has 2 elements only.
  4. The second and third period consist of 8 elements, are called the short period.
  5. The forth and the fifth period consist of 18 elements, are called the long period.
  6. The sixth and the seventh period has 32 elements.


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