1. Upto which element, the Law of Octaves was found applicable ?

Potassium

Cobalt

Calcium

Oxygen

Answer: Calcium

Explanation:


2. An element ‘A’ belongs to the third period and group 16 of the Periodic Table. Find out the valency of A. ?

Valency = 6

Valency = 3

Valency = 2

Valency = 1

Answer: Valency = 2

Explanation:


3. An element has atomic number 17. To which group, period does it belong ? It is metal or non-metal ?

17th group, 3rd period, Metal

7th group, 3rd period, Metal

7th group, 2nd period, Non-metal

17th group, 3rd period, Non-metal

Answer: 17th group, 3rd period, Non-metal

Explanation:


4. The metal which is hard and has high melting point and used in filaments of electrical bulbs is ?

Pt

W

Fe

Ni

Answer: W

Explanation:


5. A metal ‘M’ is in the first group of the Periodic Table. What will be the formula of its oxide ?

MO2

M2O3

M2O

MO

Answer: M2O

Explanation:


6. The properties of eka-aluminium predicted by Mendeleev are the same as the properties of later discovered element ?

Aluminium

Gallium

Germanium

Scandium

Answer: Gallium

Explanation:


7. Where would you locate the element with electronic configuration 2, 8 in the Modern Periodic Table ?

Group 18

Group 10

Group 2

Group 8

Answer: Group 18

Explanation:


8. The elements A, B and C belong to groups 1, 14 and 17 respectively of the Periodic Table. Which two elements will form ionic compounds ?

B and C

A and C

A and B

None

Answer: A and C

Explanation:


9. An element X combines with oxygen to form an oxide XO. This oxide is electrically con¬ducting. Write the formula of the compound formed when X reacts with chlorine ?

XCl2

XCl5

XCl

XCl3

Answer: XCl2

Explanation:


10. The atom of an element has electronic con-figuration 2, 8, 7. To which of the following elements would it be chemically similar ?

Na(11)

F (9)

P(15)

N(7)

Answer: F (9)

Explanation:

Both have same number of valence electrons