Grade IX

An atom has a mass number of 37 and atomic number 17. How many protons does it have?

• 20

• 19

• 18

• 17

What would be the atomic number of the element in whose atom the K and L shells are full?

• 10

• 12

• 14

• 16

The electronic configuration of an atom having atomic number 20 is

• 2, 8, 8, 2,

• 2, 8, 6, 4,

• 2, 4, 10, 6

• 2, 10, 5, 3

How many electrons does the outermost shell of neon have?

• 2

• 8

• 18

• 32

Almost the entire mass of an atom is concentrated in the

• Proton

• Neutron

• Electron

• Nucleus

An element has an electronic configuration of 2, 8, 7. Its valency is

• 4

• 1

• 3

• 2

Which of the following is the correct electronic configuration of Nickel with an atomic number 28?

• 1s2 2s2 2p4 3s2 3p8 3d10

• 1s2 2s2 2p6 3s2 3p6 3d10

• 1s2 2s2 2p4 3s2 3p6 3d10 4s2

• 1s2 2s2 2p6 3s2 3p6 3d8 4s2

The valency of carbon is

• 3

• 2

• 1

• 4

The symbol of Gold element is

• Na

• Au

• Hg

• Pb

Which of the following is the diatomic molecule?

• O₂

• S₈

• P₄

• O₃