Draw CO2, C in the middle and O on each side. O has 6 e- and C has 4, so 6+6+4= 14 e-.
The classified form of the following reaction should looke like that :

. WHat about the name of such reaction, I am pretty sure that it is called <span>decomposition. I bet you have the same in the option list, but next time check it carefully.</span>
Corrected question:
Bromine-88 is radioactive and has a half life of 16.3seconds. What percentage of a sample would be left after 35seconds? Round your answer to 2 significant digits.
Answer:
23% (3 significant digits)
Explanation:

where
is mass remaining
is original mass

t1/2= 16.3s , t=35s
n =35/16.3 =2.147

=
0.2258*100% =22.5%
≈23%