The answer is C, they are found in the outermost layer of the atom. hope this helps, have an amazing day :)
Yes, the forensic technique is seen reliable nowadays especially the DNA testing. DNA testing is one of the highly recommended forensic techniques since prior to forensic science process, it will undergo first into rigorous examination and validation of the specimen.
Prokaryotic cells do not contain membrane-closed organelles, (??) and they are not the same size at all. (prokaryotic are way smaller) Just to help narrow down, if I'm right! (: Sorry, I know that's not completely helpful.
1) moles = mass/mR
CaCO3 Mr = 40 + 12 + (16×3)
= 52 + 48
= 100
mass = 15
so the moles would be 15 ÷ 100
which is 0.15 moles of CaCO3
2) moles = mass ÷ Mr
Mr of Al2O3 = 27 + (16×3)
= 27 + 48
= 75
mass = 204
so the moles would be 204/75 which is 2.72 moles of Al2O3