Answer:

Explanation:
It is given that,
The radius of the inflated balloon is 7 cm.
We need to find the volume of air inside the balloon in milliliters.
The balloon is in the shape of a sphere whose volume is given by :

Hence, the volume of the air inside the balloon is
.
Answer:
Molecular solid
Explanation:
A molecular solid has a low melting point, they are soft and do not conduct electricity.
We have been told in the question that the solid does not really dissolve in water and it's solution does not improve the electrical conductivity of water. Hence, it must be a molecular solid.
Answer:
Substitution mutation
Explanation:
A substitution mutation is a type of mutation in which one or more nucleotide base is replaced by another in a sequence. This will result in the replacement of one or more amino acid in the amino acid sequence.
This is the case in this question where the original amino acid sequence was given as: Leucine – Alanine – Glycine – Leucine. After mutation, the following mutated sequence was produced: Leucine – Alanine – Valine – Leucine.
As illustrated above, one would notice that there is replacement of GLYCINE amino acid by VALINE in the mutated sequence, hence, it is an example of SUBSTITUTION MUTATION.