Answer
a. an electron has the smallest mass
b. a proton has a 1+ charge
c. an electron is found outside the nucleus
d. a neutron is electrically neutral
Work Step by Step
to answer this question you must study 'Electrical charges in Atoms' at page 111 and 'Mass of the Atom' at page 113.
Atoms are composed of subatomic particles, protons ( with positive charge +1 and heavy mass), electrons ( with negative charge -1 and small mass) and neutrons ( with no charge and about the same mass of protons)
Remember, only neutrons and protons can be found inside the nucleus
