Periodic Classification of Elements.Chapter No. 2, SSC Science and Technology

Periodic Classification of Elements



Column I
Column 2
Column 3
i. Triad
a. Lightest and negatively charged particle in all the atoms.
1. Mendeleev
ii. Octave
b. Concentrated mass and positive charge.
2. Thomson
iii. Atomic Number
c. Average of the first and the third atomic mass
3. Newlands.
iv. Period
d. Properties of the eight element similar to the first.
4. Rutherford.
v. Nucleus
e. Positive charge on the nucleus.
5. Dobereiner
vi. Electron
f. Sequential change in molecular formulae
6. Moseley

Ans. (i – c – 5 ) , (ii – d – 3) , (iii – e – 6 ) , (iv – f – 1) , (v – b – 4), (vi - a – 2).

a. The number of electrons in the outermost shell of alkali metals is ……………………..

          i. 1
          ii. 2
          iii. 3
          Iv. 7
b. Alkaline earth metals have valency 2. This means that their position in the modern periodic table is in ………………

          i. Group 2
          ii. Group 16
          iii. Period 2          
          iv. d – block.
c. Molecular formula of the chloride of an element X is XCl. This compound is a solid having high melting point. Which of the following elements be present in the same group as X.

          i. Na
          ii. Mg
          iii. Al
          Iv. Si
d. In which block of the modern periodic table are the nonmetals found?

          i. s - block
          ii. p - block
          iii. d - block
          iv. f – block.

6. Write short notes:

7. Write Scientific reasons.


Find out the applications of all the inert gases, prepare a chart and display it in the class.

Important Extra Questions, on this chapter that may come in your Board Exam.



Why is atomic number said to be a fundamental property?

What should be the position of Hydrogen in the Modern Periodic Table ? Why?

The atomic number of an element X is 17. Predict :

Read the following descriptions and decide whether the element belongs to metal or non-metal. Justify your answer.

How do you calculate valency of an element from its electronic configuration ?

How are isotopes of different elements placed in the Modern Periodic Table ?

Explain the zig-zag line in the periodic table.

Explain the features of Mendeleev's periodic table.