Elements And Metals : 1

Question 1 :

Brass gets discoloured in air because of the presence of which of the following gases in air?

A). Oxygen
B). Hydrogen sulphide
C). Carbon dioxide
D). Nitrogen
Answer : Option B

Question 2 :

Which of the following is a non metal that remains liquid at room temperature?

A). Phosphorous
B). Bromine
C). Chlorine
D). Helium
Answer : Option B

Question 3 :

Chlorophyll is a naturally occurring chelate compound in which central metal is

A). copper
B). magnesium
C). iron
D). calcium
Answer : Option B

Question 4 :

Which of the following is used in pencils?

A). Graphite
B). Silicon
C). Charcoal
D). Phosphorous
Answer : Option A

Question 5 :

Which of the following metals forms an amalgam with other metals?

A). Tin
B). Mercury
C). Lead
D). Zinc
Answer : Option B

Question 6 :

Chemical formula for water is

A). NaAlO2
B). H2O
C). Al2O3
D). CaSiO3
Answer : Option B

Question 7 :

The gas usually filled in the electric bulb is

A). nitrogen
B). hydrogen
C). carbon dioxide
D). oxygen
Answer : Option A

Question 8 :

Washing soda is the common name for

A). Sodium carbonate
B). Calcium bicarbonate
C). Sodium bicarbonate
D). Calcium carbonate
Answer : Option A

Explanation :

What is the scientific name for washing soda?
Sodium carbonate (also known as washing soda or soda ash), Na2CO3 is a sodium salt of carbonic acid.
Scientific name for baking soda?
Sodium bicarbonate or sodium hydrogen carbonate is the chemical compound with the formula NaHCO3. Sodium bicarbonate is a white solid that is crystalline but often appears as a fine powder. Since it has long been known and is widely used, the salt has many related names such as baking soda, bread soda, cooking soda, and bicarbonate of soda.

Question 9 :

Quartz crystals normally used in quartz clocks etc. is chemically

A). silicon dioxide
B). germanium oxide
C). a mixture of germanium oxide and silicon dioxide
D). sodium silicate
Answer : Option A

Question 10 :

Which of the gas is not known as green house gas?

A). Methane
B). Nitrous oxide
C). Carbon dioxide
D). Hydrogen
Answer : Option D

Explanation :

In order, the most abundant greenhouse gases in Earth's atmosphere are:
* water vapor
* carbon dioxide
* methane
* nitrous oxide
* ozone
* chlorofluorocarbons

Question 11 :

Bromine is a

A). black solid
B). red liquid
C). colourless gas
D). highly inflammable gas
Answer : Option B

Question 12 :

The hardest substance available on earth is

A). Gold
B). Iron
C). Diamond
D). Platinum
Answer : Option C

Question 13 :

The variety of coal in which the deposit contains recognisable traces of the original plant material is

A). bitumen
B). anthracite
C). lignite
D). peat
Answer : Option D

Question 14 :

Tetraethyl lead is used as

A). pain killer
B). fire extinguisher
C). mosquito repellent
D). petrol additive
Answer : Option D

Question 15 :

Which of the following is used as a lubricant?

A). Graphite
B). Silica
C). Iron Oxide
D). Diamond
Answer : Option A

Question 16 :

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

A). Argon
B). Xenon
C). Helium
D). Krypton
Answer : Option C

Question 17 :

The gases used in different types of welding would include

A). oxygen and hydrogen
B). oxygen, hydrogen, acetylene and nitrogen
C). oxygen, acetylene and argon
D). oxygen and acetylene
Answer : Option D

Question 18 :

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

A). osmosis
B). deliquescence
C). efflorescence
D). desiccation
Answer : Option B

Question 19 :

In which of the following activities silicon carbide is used?

A). Making cement and glass
B). Disinfecting water of ponds
C). cutting very hard substances
D). Making casts for statues
Answer : Option C

Question 20 :

The average salinity of sea water is

A). 3%
B). 3.5%
C). 2.5%
D). 2%
Answer : Option B

Question 21 :

When an iron nail gets rusted, iron oxide is formed

A). without any change in the weight of the nail
B). with decrease in the weight of the nail
C). with increase in the weight of the nail
D). without any change in colour or weight of the nail
Answer : Option C

Question 22 :

Galvanised iron sheets have a coating of

A). lead
B). chromium
C). zinc
D). tin
Answer : Option C

Question 23 :

Among the various allotropes of carbon,

A). coke is the hardest, graphite is the softest
B). diamond is the hardest, coke is the softest
C). diamond is the hardest, graphite is the softest
D). diamond is the hardest, lamp black is the softest
Answer : Option C

Question 24 :

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

A). transition metals
B). main group metals
C). alkali metals
D). rare metals
Answer : Option A

Question 25 :

Heavy water is

A). deuterium oxide
B). PH7
C). rain water
D). tritium oxide
Answer : Option A