The basic building block of matter is the atom.
Answer:
the answer is d.
Explanation:
because the core is deepest then is the mantle and the lithpsphere is last .
I put a picture incase you need a visual example.
Answer:
D. Protons ; neutrons.
Explanation:
For a given element the number of protons is fixed, but the number of neutrons differ because the element usually consist of a number of isotopes.
For example Carbon has isotopes which contain 12, 13 and 14 neutrons.
So that is why you average the number of neutrons to find the approximate atomic mass..
Chlorine-36 has been widely used for dating old groundwater.