Answer:
* android noises *
Explanation:
I don’t think they have to
How do the number of electrons in the second energy shell of an atom change going across period 2 in the periodic table?
The answer is: A. The number of electrons increases by 1, from left to right.
B is wrong because atoms in period 2 DO have a second energy shell. For C, the number of electrons in the second energy shell is NOT full. For D, it is wrong to state that the number of electrons increases by 1, from right to left.
Mass/moles x mr
so you need to work out the rfm of Ca(OH)2= 40(16+1)2= 40+34= 74
and then use the formula= moles x mr
6.25 x 74= 462.5
Answer= 462.5g
