C. The neutron number.
An element is determined based on how many protons has, if the protons number change then you got a new element.
If the number of neuron change you got the same element except it will be a bit heavier or lighter if you are gaining or loosing neutrons. Those variations of an element are called the isotops of the element.
The protons and neutrons toghether form the nucleus of the atom that is heavy and dense as an elephant.
The electrons are light as fleas and stay on the shels of around the nucleus and if they are more then the number of protons they make the atom negatively charged and vice versa.
Answer:
Mass = 217.30 g
Solution:
Mass and moles are related to each other as,
Moles = Mass / M.mass ---- (1)
Where;
Moles = 3.42
M.Mass = 63.54 g.mol⁻¹
Solving eq. 1 for Mass,
Mass = Moles × M.mass
Putting Values,
Mass = 3.42 mol × 63.54 g.mol⁻¹
Mass = 217.30 g
I think it is the first choice
Hope that helped!
Temperature is a measure of "Molecular movement"
In short, Your Answer would be Option B
Hope this helps!
