Answer:
a
The condensed structural formula for methane is
![CH_4](https://img.qammunity.org/2021/formulas/chemistry/high-school/q5lwp1s901gufhom6so2dqdlulnzauk78c.png)
b
The condensed structural formula for ethane is
![CH_3 CH_3](https://img.qammunity.org/2021/formulas/chemistry/college/kphefr0eigfe5rhgi9bsa7hctr0z9chpfy.png)
c
The condensed structural formula for pentane is
d
The diagram for the structural formula for cyclopropane is shown on the first uploaded image
Step-by-step explanation: