Please help me with this question please just help me with what is this is or synthesis singlereplacement combustion
decomposition
double replacement

You use the atomic number to find out how many protons and neutrons there are in the atom. you use the atomic mass to find out how many protons and electrons there are in the atom. 

There is no reason to think the results are biased or not conducted properly but you should not assume the results are correct just because they were done in a laboratory so the answer would be c. it is likely to be reliable because the results support the conclusion presented.

Its the second one nonmetals are moldable and easily shaped 

Ithink about 50 % of an original isotope's number of atoms remain