Question

1. if a heavy - metal has an unstable nucleus, the instability could be reduced by

i. making neutrons and protons approximately equal
ii. increasing its nuclear size
iii. making the nuclide undergo decay
a. i and ii only
b. ii and iii only
c. i and iii only
d. i, ii and iii

1. the process involved in the production of ethanol from sugarcane is

a. esterification.
b. neutralization.
c. fermentation.
d. saponification.

1. which of the following statements about allotropes is correct?

a. atoms with different number of neutrons but same number of protons.
b. different forms of an element in the same physical state.
c. molecules with the same molecular formula but different structures.
d. molecules that absorb water vapour on exposure to air.

1. gas x diffuses twice as fast as gas y under the same conditions. if the relative molecular mass of x is 28, the relative molecular mass of y would be

a. 120.
b. 56.
c. 112.
d. 14.

1. which of the following gases turns red litmus paper blue?

a. co₂
b. nh₃
c. hcl
d. so₂

Explanation:

15.

• For I: A more balanced ratio of neutrons to protons can stabilize a nucleus.
• For II: Increasing nuclear size doesn't reduce instability; in fact, larger nuclei are often more unstable.
• For III: Decay helps a nuclide reach a more stable state.

The conversion of sugar in sugar - cane to ethanol occurs through the process of fermentation by yeast.

Allotropes are different forms of an element in the same physical state.

Answer:

C. I and III only

16.