Answer:
a
The condensed structural formula for methane is

b
The condensed structural formula for ethane is

c
The condensed structural formula for pentane is
d
The diagram for the structural formula for cyclopropane is shown on the first uploaded image
Explanation:
55.5 I think but I may be wrong
Sulfur would be the answer
Answer:
The ground state electron configuration of ground state gaseous neutral tin is [Kr]. 4d10. 5s2. 5p2 and the term symbol is 3P0.