An electron is in a region outside the nucleus. An electron a) Is larger than a proton and has no charge
b) Has less mass than a proton and has a negative charge
c) Is smaller than a proton and has no charge
d) Has a positive charge

b

Explanation:

electrons lie in the orbits of the atom. they are negatively charged and they are very small in size. they have very less mass than proton. ele tron has 1/1840 mass of proton.

answer:

technetium is the most reactive. this is followed by silver. the least reactive out of these three elements is strontium.