Marcy tests a solution with a strip of blue litmus paper. The paper turns red. The solution is . acidic
basic
neutral

i think it's c. if you look search electronic symbol on google and then click on wiki it shows you a

nuclear fission produces elements that are heavier than helium.

the elements that are used in nuclear fission and their products are much heavier than helium.

answermeridional ;

5 structural isomers

the isomers are:

n-exane :   ch3ch2ch2ch2ch2ch3

2-methylpentane :   ch3ch(ch3)ch2ch2ch3

3-methylpentane :   ch3ch2ch(ch3)ch2ch3

2,3-dimethylbutane :   (ch3)2chch(ch3)2

2,2-dimethylbutane :   (ch3)3cch2ch3