Periodic classification of elements Worksheet-3

Periodic classification of elements Worksheet-3

 

  1. Which of the following statements is correct?

A. Sodium atom is larger in size than Potassium atom

B. Sodium atom is larger in size than Lithium atom

C. Chlorine atom is larger in size than Sodium atom

D. Aluminium atom is larger in size then a sodium atom

 

  1. An atom of an element has electronic configuration 2, 8, 1. Which of the following statement is correct?

A. The valency of element is 7

B. The element exists as a diatomic molecule

C. The element is of non-metallic nature

D. The element forms a basic oxide

 

  1. Arrange the following in the increasing order of their atomic radius : Na, K, Mg, Rb

A. Mg < K < Na < Rb                  B. Mg  < Na < K < Rb

C. Mg < Na < Rb < K                  D. Na < K < Rb < Mg

 

  1. The radii of Li, Na, K are order _____.

A. K > Na > Li                               B. K > Na < Li

C. K < Na < Li                               D. Li > Na < K

 

  1. Which of the following has smallest size?

A. Mg                  B. Na                  C. Al                    D. Si

 

  1. Which one of the following is expected to have largest size?

A. F                     B. O                     C. Al                    D. N

 

  1. The statement that is not correct for the periodic classification of elements is_____.

A. The properties of elements are the periodic functions of their atomic numbers

B. Non-metallic elements are lesser in number than metallic elements

C. The size of atom doesn’t vary in a group

D. The valency of elements remains the same in a group

 

  1. Which of the following properties show gradual decrease with increase in atomic number across a period in the periodic table?

A. Valency                                      B. Non-metallic character

C. Acidic nature of oxides          D. Size of atom

 

  1. On going from right to left in a period in the periodic table the metallic character of the elements____.

A. Increases

B. Decreases

C. Remain unchanged

D. Decreases first then increases

 

  1. Atom of which of the following element has largest size?

A. F                     B. He                  C. N                     D. Na

 

Answer Key:

  1. B

Explanation: Size of atom decreases from left to right in a period and increases from top to bottom in a group.

  1. D

Explanation: The given electronic configuration is of sodium (atomic number 11). Sodium is a metal and it forms basic oxides.

  1. B

Explanation: Atomic radius increases from top to bottom in a group and decreases from left to right in a period.

  1. A

Explanation: Ionic radii increase down the group in the periodic table.

  1. D

Explanation: Si atom is smallest in size as the size of atom decreases from left to right in a period in the periodic table.

  1. D

Explanation: Al has the largest size. Size of atom decreases from left to right in a period

  1. C

Explanation: The size of atom decreases from left to right in a period in periodic table.

  1. D

Explanation: Size of atom decreases from left to right in a period. Whereas Valency increases and then decreases, Non-metallic character increases, and acidic nature of oxides also increase.

  1. B

Explanation: Metallic character of the elements decreases as the size of atom of element decreases and its tendency to loose electron also decreases.

  1. D

Explanation: Sodium has largest size as size of atom decreases from left to right in a period.