An atom typically has a neutral charge, as in most cases an atom has the same amount of positively charged protons as it does negatively charged electrons.
Atoms that do not have the same amount of electrons as protons are known as isotopes.
Answer: 3.13 g
Explanation:
Radioactive decay follows first order kinetics.
Half-life of uranium-232 = 68.8 years
N = amount left after time t
= initial amount
= rate constant
t= time
= 100 g, t= 344 years, 
N=3.13g
Answer:
E. Gain of electrons
Explanation:
A reduction reaction is one part of the two concurrent reactions that take place in a redox (reduction-oxidation) reaction.
During reduction, an atom gains electrons from a donor atom, and it's oxidation number becomes smaller.
Option A is wrong because reduction does not increase oxidation state nor are neutrons involved
Option B is wrong because reduction is not a nuclear reaction (does not involve the nucleons)
Option C is wrong because reduction leads to reduction in oxidation state
Option D is wrong leads to a reduction in oxidation state when electrons are gained
Option E is correct because reduction involves gain of electrons
