How many neutrons could an atom of the element zinc (zn) have?
im confused because its multiple choice and the only options are 30, 36, 65, and i dont know which one it is. can someone ?

none of these

Explanation:

because no.of proton+no.of neutron=atomic mass

therefore in zinc no.of protons(30)+ no.of neutrons(35) =atomic mass(65)

therefore the no.of neutrons in zinc is 35

c) 50% there are four chromosomes. after crossing over, 2 of the four have been changed. that means any gamete has a 2 in 4 chance or 50% chance of receiving the mutated chromosome.