Answer: last one is right
Explanation: atoms of same element have always same number of protons but may have several isotopes which have different number of neutrons.
Atomic theory is the scientific inquiry of the nature of matter, which is subject to change as new information is discovered. The answer is A.
Mass percent is one way of expressing concentration of a solution. It is expressed as the mass of solute per mass of solution. For this case, mass percent is calculated as follows:
% mass = 140 g NaCl / (140 g NaCl + 4500 mL ( 0.997 g/mL)) x 100
% mass = 3.03 %
Usally it may seem like it but it doesn't. It just has ilussion for it and this happens because the cloths are being spinned round and round in the same direction
<span>X: Geothermal energy
Y: Nonrenewable
So the answer is A</span>
