GK Science

 Brass gets discoloured in air because of the presence of which of the following gases in air?
     Ans:Hydrogen sulphide

Chlorophyll is a naturally occurring chelate compound in which central metal is:
   Ans:Magnesium

Which Element is used in pencils?
   Ans:Graphite

The gas usually filled in the electric bulb is:
   Ans:Nitrogen

The hardest substance available on earth is:
   Ans:Diamond

Tetraethyl lead is used as:
   Ans:petrol additive

The inert gas which is substituted for nitrogen in the air used by deep sea divers for breathing, is:
  Ans:Helium

The property of a substance to absorb moisture from the air on exposure is called:
  Ans:deliquescence

The average salinity of sea water is:
       Ans:3.5%

The group of metals Fe, Co, Ni may best called as:

    Ans:Transition Metals

Non stick cooking utensils are coated with:

   Ans:Teflon

Monazite is an ore of:

  Ans:Thorium

Carbon, diamond and graphite are together called:

   Ans:Allotropes

Potassium nitrate is used as:

   Ans:Fertiliser

Most soluble in water is:

   Ans:Sugar

Sodium metal is kept under:

   Ans:kerosene

Which are the ingredients of gun metal?

 Ans:Copper, Tin

From which mineral is radium obtained?

  Ans: Pitchblende

What is laughing gas?

  Ans:Nitrous Oxide

Actinides are the elements with atomic numbers from:

    Ans: 89 to 103

acinides are seen in the bottom of the periodic table

The two elements that are frequently used for making transistors are:

     Ans:  silicon and germanium

Diamond is an allotropic form of:

    Ans: carbon

In fireworks, the green flame is produced because of:

   Ans: barium

LPG consists of mainly:

   Ans: methane, butane and propane

Production of chlorofluorocarbons (CFC) gas which is proposed to be banned in India, is used in which of the following domestic products?

  Ans: Refrigerator

Potassium Permanganate is used for purifying drinking water, because:

  Ans:it is an oxidising agent