It would have THREE rings/energy levels. This is because of the amount of electrons each orbital can hold.
Endothermic is a chemical reaction which absorbs energy in the form of heat
I am not completely sure what your question is, but I think you are asking about the molar mass? It is a mole conversion. For example, if you start with atoms and want grams, you would need to get rid of the atoms unit first then get rid of the mols unit: so you would have to multiply it by (1 mol / Avogadro's number) X (molar mass / 1 mol) = this is the conversion factor that gives you grams. I hope this helped!
Have a fantastical day,
Em
False.Energy does not involve motion
No, the two isotopes of lithium-6 and lithium-7 are not equally common.
The more plentiful isotope would be lithium-7.
This can be easily demonstrated by assuming that both isotopes were equally common. If that were the case, the average atomic mass would be (6 + 7)/2 = 6.5 amu. Now compare that value if they were both equal to the actual value found in nature. The value found in nature is 6.941 amu which is heavier than the 6.5 amu that would happen if they were equally common. Since the natural value is heavier, that means that there has to be more of the heavier isotope than there is of the lighter one. Therefore lithium-7 is more common than lithium-6.