Tag: chemistry

Questions Related to chemistry

Which among the following non-metal is liquid at room temperature?

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. Bromine

  3. Mercury

  4. Phosphorous

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Correct Option: B
Explanation:

Mercury and bromine both are present in liquid state at room temperature but mercury is metal and bromine is non-metal.

So, liquid non-metal at room temperature is bromine.

Non-metals are usually poor conductors of heat and electricity. They are non-lustrous, non-sonorous, non-malleable and are coloured. The non-metal which is known to form the largest number of compounds is:
chemistry composition of matter physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. carbon

  2. sulphur

  3. nitrogen

  4. chlorine

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Correct Option: A
Explanation:
Carbon is a non-metal and is  known to form the largest number of compounds due to two reasons:

  1. Catenation - The ability of carbon to form bonds with the atoms of itself resulting in the large chains and rings of carbon. It causes large no. of chain and ring compounds.
  2. Tetravalency - Due to tetravalency, carbon can form bonds with other tetravalent elements and monovalent elements like hydrogen, chlorine, bromine etc.

Hence, option A is correct.

Which of the following element is not in the liquid state at room temperature?

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

  1. $Hg$

  2. $Li$

  3. $Ga$

  4. $Br$

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Correct Option: B
Explanation:
Bromine and mercury are metal which is liquid at room temperature. Gallium a brittle solid at low temperatures, and a liquid at temperatures greater than $29.76^o C$ (slightly above room temperature).Thus gallium is liquid at room temperature.
Bromine is a liquid because electrons are well apart from the nuclei so they are easily distorted .Intermediate intermolecular forces exists and thus it is in liquid state.
 Lithium  is a solid at room temperature.

Sulphur extracted from natural sources is called roll sulfur.

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

  1. True

  2. False

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Correct Option: B
Explanation:

Sulphur extracted from natural sources is called brimstone. 

B is correct

The metallic character of elements ............. in a group from top to bottom.

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

  1. Increases

  2. Decreases

  3. remains constant

  4. shows indefinite behaviour

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Correct Option: A

Eventhough a cinema hall is a place prone to fire hazards, the interiors are mostly made of wood or wood based panels. Why is this so ?

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

  1. Wood does not catch fire easily

  2. Wood is opaque

  3. Wood can absorb sound

  4. Wood is very commonly available

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Correct Option: C
Explanation:

Wood is a good sound absorber. if it will be of some different material then there will be echo(a reflection of sound) in the hall and the sound will not be clear.

Most balloons, tyres and footballs are made-of rubber. This is because rubber is:

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

  1. naturally available

  2. cheap

  3. an electrical insulator

  4. soft and flexible

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Correct Option: D
Explanation:

Prior to rubber tires, metal and wood were the materials in use. However it was found that natural Rubber provides better cushioning, makes less noise. Further rubber deforms under weight /force which results in larger contact patch with the road than with metal/wood tires of same diameter/width. During cornering at high speeds, the deformation of sidewall and larger contact area improves the traction or grip on the road increasing safety.

Which one of the following oxidation states is not possible in metal carbonyls ?

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

  1. +1

  2. 0

  3. -1

  4. +2

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Correct Option: B

Which of the following statements are true about metals?

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

  1. Valence band overlaps with conduction band.

  2. The gap between valence band and conduction band is negligible.

  3. The gap between valence band and conduction band cannot be determined.

  4. Valence band may remain partially filled.

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Correct Option: A
Explanation:

Valence band overlaps with conduction band for the conductivity of metal.

What is the change in color when $ZnO$ is heated?

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

  1. Yellow

  2. Violet

  3. Green

  4. Blue

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Correct Option: A
Explanation:
Zinc Oxide is originally a white powder. When heated up, it turns yellow but does not decompose and when it is removed from the heat it gradually goes back to its original white colour.

Hence, option A is correct.