Chemistry-8-10

What is the valency of Iron?

• 5 or 6

• 2 or 3

• 1 or 2

• 1 or 3

What is the atomic number of Oxygen?

• 6

• 7

• 8

• 9

Which element is a noble gas?

• Hydrogen

• Helium

• Carbon

• Oxygen

What is the chemical symbol for Gold?

• Au

• Ag

• Fe

• Cu

Which of the following is an example of electrovalent compound?

• Carbon dioxide (CO2)

• Water(H2O)

• Sodium chloride (NaCl)

• Methane(CH4)

Answer explanation

Sodium chloride (NaCl) is an example of an electrovalent compound due to the ionic bond between sodium and chlorine atoms.

How many electrons does a neutral Helium atom have?

• 1

• 2

• 3

• 4

What is the molecular formula of calcium carbonate?

• CaO

• CaCl2

• CaCO2

• CaCO3

How many valence electron are there in Magnesium?

• 2

• 4

• 6

• 1

How many protons are there in a Carbon atom?

• 4

• 6

• 8

• 12

Which of the following is a halogen element?

• Neon

• Argon

• Chlorine

• Krypton

Answer explanation

Chlorine is a halogen element, while Neon, Argon, and Krypton are noble gases.