Science Assertion & Reason

Assertion (A): Hard water limits the cleaning action of soap.
Reason (R): When combined with soap, hard water develops a thin layer.
(a) Both (A) and (R) are correct, (R) explains (A)
(b) (A) is correct but (R) is wrong
(c) (A) is wrong but (R) is correct
(d) Both (A) and (R) are correct, but (R) doesn’t explain (A).

Assertion (A): Ethanol has a much higher boiling point than ethane.
Reason (R): Presence of hydrogen bond in a molecule increases the boiling point.
(a) Both (A) and (R) are correct, (R) explains (A)
(b) (A) is correct but (R) is wrong
(c) (A) is wrong but (R) is correct
(d) Both (A) and (R) are correct, but (R) doesn’t explain (A).

Assertion (A): Carbon compounds have low melting and boiling points and they are easily combustible.
Reason (R): Carbon compounds are electrovalent compounds.
(a) Both (A) and (R) are correct
(b) (A) is correct but (R) is wrong
(c) Both (A) and (R) are wrong
(d) (A) is wrong but (R) is correct.

Assertion (A): Carbon combines with many other elements to form various stable compounds.
Reason (R): The stability of carbon compounds is due to the small size of carbon which enables the nucleus to hold on to the shared pair of electrons strongly.
(a) Both (A) and (R) are wrong
(b) Both (A) and (R) are correct
(c) (A) is correct but (R) is wrong
(d) (A) is wrong but (R) is correct.

Assertion (A): Graphite is a good conductor of electricity, unlike other non – metals.
Reason (R): Graphite has free electrons in it.
(a) Both (A) and (R) are correct
(b) (A) is correct but (R) does not explain (A)
(c) (A) is wrong but (R) is correct
(d) Both (A) and (R) are wrong.

Assertion (A): Diamond is a rigid substance and it is very hard.
Reason (R): In diamond, each carbon atom is bonded to three other carbon atoms in the same place giving hexagonal layers held together by weak van der Waals forces.
(a) Both (A) and (R) are correct
(b) (A) is correct but (R) does not explain (A)
(c) Both (A) and (R) are wrong
(d) (A) is wrong but (R) is correct.

Assertion (A): Methane is formed when four electrons of carbon are shared with four hydrogen atoms.
Reason (R): This characteristic of a carbon atom by virtue of which it forms four covalent bonds is referred to as tetra valency of carbon.
(a) (A) is correct and (R) explains (A)
(b) Both (A) and (R) are wrong
(c) (A) is correct but (R) does not explain (A)
(d) (A) is wrong but (R) is correct.

Assertion (A): Carbon chemistry is called as living chemistry.
Reason (R): The carbon atoms form the building blocks of living organisms and carbon combined with other atoms decide life on earth.
(a) Both (A) and (R) are wrong
(b) Both (A) and (R) are correct
(c) (A) is correct but (R) is wrong
(d) (A) is wrong but (R) is correct.

Assertion (A): Carbon compounds hold the key to plant and animal life on the earth.
Reason (R): Carbon circulates through air, plants, animals and soil by means of complex reactions.
(a) Both (A) and (R) are correct
(b) Both (A) and (R) are wrong
(c) (A) is correct but (R) is wrong
(d) (A) is wrong but (R) is correct.