Answer:
13
Explanation:
proton plus neutron equal to atomic mass
An ion has a positive or negative charge. While a covalent bond always has no charge, meaning it is neutral.
Answer:
equal the number of electrons.
Explanation:
Answer:
n=6 to n=3 (B)
Explanation:
Energy of an electron present in the 
orbit is directly proportional to 
.Hence a transistion from one orbit to another orbit emits an energy proportional to the difference of their squares of the orbits. that is if an electron travels from orbit n1 to orbit n2 then it emits an energy corresponding to 
.So in the above question the highest energy emission occurs when an electron moves from n=6 to n=3.(Highest difference of energy levels).
