Select the correct answer. Which particles make up the nucleus of an atom?
O A.
protons and electrons
OB.
neutrons and electrons
O C.
protons only
OD.
protons and neutrons
O E.
neutrons only

OD. Protons and neutrons

Explanation: They are both in the nucleus. The electrons are outside.

answer: the rock sample is a sedimentary rock.

explanation:

it is given that:

mass of rock sample, m = 2.7 g

volume of rock sample,

so, density of rock sample will be

since, the density of rock sample is . hence, the rock sample is a sedimentary rock, whose densities varies between .

none, its a machine