Tag: chemistry

Questions Related to chemistry

Which of the following is suitable to make raincoats?

chemistry composition of matter physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. Cotton

  2. Plastic

  3. Silk

  4. Wool

Show answer
Correct Option: B
Explanation:

Plastic is waterproof, it cannot absorb water while the others can.

A mirror is:

chemistry composition of matter physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. opaque

  2. transparent

  3. translucent

  4. none of these

Show answer
Correct Option: A
Explanation:

A silver glass mirror is an ordinary mirror, coated on its back surface with silver, which produces images by reflection. This kind of glass mirror is produced by coating a silver, copper film and two or more layers of waterproof paint on the back surface of float glass, which perfectly resists acid and moisture.

As it reflect all the light falling on it and we can see through it so it is a opaque.

Diamond and boron are soft non-metals.
chemistry metals physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

The given statement is false as diamond and boron are the hard non-metals.

Which of the following is not a correct statement?

chemistry composition of matter physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. Non-metals melt at low temperature

  2. Non-metals are generally bad conductors of heat and electricity

  3. Non-metals are non-sonorous

  4. Non-metals are malleable

Show answer
Correct Option: D
Explanation:

Non-metals are malleable, is an incorrect statement.

Which among the following is a non-metal?

chemistry composition of matter physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. Bromine

  2. Zinc

  3. Sodium

  4. Iron

Show answer
Correct Option: A
Explanation:

Bromine is a liquid non-metal. Rest others are metals.

The non-metal which is liquid at room temperature is:

chemistry composition of matter physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. chlorine

  2. fluorine

  3. bromine

  4. iodine

Show answer
Correct Option: C
Explanation:

Bromine is the only non-metal which is liquid and diatomic molecule at room temperature. 

It is a dense, reddish-brown liquid evaporating at standard temperature and pressure to give an orange vapour. It is one of the only two elements on the periodic table that are liquids at room temperature other than mercury.

Hence, option $C$ is correct.

All non-metals are bad conductor of heat and electricity.

chemistry composition of matter physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

Most of the non-metals are bad conductor of heat and electricity. But there are some non-metals which conduct electricity for example graphite. Due to presence of free electron in it.

Why are non-metals poor conductors of electricity?

chemistry metals physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. They have high melting point

  2. They vibrate at high speed

  3. They do not have free electrons

  4. All of above

Show answer
Correct Option: C
Explanation:

Non-metals are not dense enough and do not have enough free electrons to pass electricity efficiently. Electrons in non-metals are held tightly , they are no allowed to move freely .

Which of the following example is a poor conductor of electricity?

chemistry metals physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. Oxygen

  2. Aluminium

  3. Gold

  4. Silver

Show answer
Correct Option: A
Explanation:

Oxygen is a non-metal. Non-metals do not have enough free electrons to pass electricity. Electrons in non-metals are held tightly, they are not allowed to move freely .

State True or False.
Non-metals are good conductors of heat.

chemistry metals physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

Non-metals are poor conductors of heat because non-metal compounds do not have a metallic structure, which benefits heat conduction.