Can anyone check my chemistry answers?

I check all of them. most of them correct but one

in question 6, the answer is the third choice. remember to find the neutrons, you take the atomic mass minus the atomic number. 38 - 18= 20

The  grandmother cell  is a hypothetical  neuronthat represents a complex but specific concept or object.[1]  it activates when a person "sees, hears, or otherwise sensibly discriminates"[2]  a specific entity, such as his or her grandmother. the term was in use at least as early as 1966 amongst staff and students in the department of experimental psychology, university of cambridge, england. a similar concept, that of the  gnostic neuron, was proposed two years later

Carbon based or cells?