a particle of fluorine shows 9 protons and 18 electrons. is this an atom or an ion? what’s the charge?

Ion i think

Explanation:

I think ion's contain more negative energy from electrons and since it's -18 and 9+ it would be -9 if u add them up

after receiving a stimus, the sensory receptors send(s) signals to the appropriate area of the body.  

the must be sensory neurons.  

hope its .

the correct option is option d