The highest point is the crest
Explanation
Radius of neon atom : 69 pm = 
Volume occupied by the one atom:

given that
atoms are present in 1L
1 L = 0.001 
The volume occupied by the
neon atoms

Fraction of volume occupied by the neon atom:


The fraction of of volume occupied by the neon atom is very less than the 1 L which indicates the presence of large amount of empty space between the atoms of the gas.
Answer:
Carbon dioxide is used as a refrigerant, in fire extinguishers, for inflating life rafts and life jackets, blasting coal, foaming rubber and plastics, promoting the growth of plants in greenhouses, immobilizing animals before slaughter, and in carbonated beverages.
The answer would be B since it forms a solid
Hi
Alpha decay is a type of radioactive decay.
So, when Alpha decay goes through a process called "radioactive process", two neutrons and two protons comes together and is ejected from the nucleus of a radioactive atom.
Hope this helped :)