Answer:
If you change the number of neutrons somehow, nothing will happen because it carry's no charge at all.
Explanation:
For the first one it’s 69 just count the little lines from the side.
Answer:
See Explanation
Explanation:
The question is incomplete; as the mixtures are not given.
However, I'll give a general explanation on how to go about it and I'll also give an example.
The percentage of a component in a mixture is calculated as:

Where
E = Amount of element/component
T = Amount of all elements/components
Take for instance:
In 
The amount of all elements is: (i.e formula mass of
)



The amount of calcium is: (i.e formula mass of calcium)



So, the percentage component of calcium is:




The amount of hydrogen is:



So, the percentage component of hydrogen is:




Similarly, for oxygen:
The amount of oxygen is:



So, the percentage component of oxygen is:




Na₃PO₄ -----> 3Na(+) + PO₄(3-)
y-y.......................3y...........y
3y = 1.2
y = 0,4M
Na₃PO₄ -----> 3Na(+) + PO₄(3-)
0,4-0,4..............1,2..........0,4
0.........................1,2..........0,4
C = n/V
n = C×V
n = 0,4×0,65L
n = 0,26 mol Na₃PO₄
mNa₃PO₄: (23×3)+31+(16×4) = 164 g/mol
164g ----- 1 mol
Xg -------- 0,26 mol
X = 164×0,26
X = 42,64g Na₂SO₄