The elements in the first period of the periodic table are _____.

1. 1. Hydrogen and Helium
   2. Hydrogen, Nitrogen and Oxygen
   3. Hydrogen, Helium and Carbon
   4. Hydrogen, Helium, Nitrogen and Oxygen

Cooling of vapours of some compounds change them directly into solid state. This phenomenon is called _____.

1. 1. 1. Sublimation
      2. Condensation
      3. Evaporation
      4. Crystallisation

“Firdous Al Hikmat Fe Ilmul Kemia” was written by _____.

1. 1. Al-Beruni
   2. Jabir bin Haiyan
   3. Bu Ali Sina
   4. Khalid bin Yazeed

Methane is used in daily life with the name of _____.

1. 1. Natural gas
   2. Carbon dioxide
   3. Carbon monoxide
   4. Calcium carbonate

When electricity is passed through neon, it glows _____.

1. 1. Blue
   2. Red
   3. Yellow
   4. Green

Argon and which gas is used in various types of fluorescent and phototubes?

1. 1. Helium
   2. Oxygen
   3. Krypton
   4. Neon

Which of the following is the purest form of carbon?

1. 1. Diamond
   2. Graphite
   3. Marble
   4. Bucky ball

The water that can produce good lather with soap is known as _____.

1. 1. Atomic water
   2. Hard water
   3. Heavy water
   4. Soft water

The glitter of diamond is _____.

1. 1. because it is transparent
   2. due to its quality of reflecting light
   3. because it is a non-conductor
   4. because of its density

In which of the following layers of atmosphere is Ozone present?

1. 1. Troposphere and Stratosphere
   2. Troposphere and Thermosphere
   3. Thermosphere
   4. Mesosphere