Given,
The two isotopes of B are 10B and 11B
% abundance of 10B = 19.80
% abundance of 11B = 80.20
Average atomic mass of B
= 
= 
= 
= 
= 10.802
Therefore, the average atomic mass of B is 10.802 u
Yes; every object has energy and you cannot create or destroy energy but you can transfer it.
The answer is 9. Calcium nitrate is made up
of 3 different elements that equal 9 atoms.
Answer: 4.74 moles
Explanation:

Moles of Ba=
Moles of Ba=
According to given balanced equation,
1 mole of Barium gives 2 moles of Li
Thus 2.37 moles of Barium gives=
Thus 4.74 moles of lithium will be produced by 135 g of barium.
Answer:
Hey!
Your answer is 45kg.m/s
Explanation:
Using the formula P=M x V
(p=momentum...M=mass...V=velocity)
We do M x V
15 x 3
Which gives us an answer of 45kg.m/s!
HOPE THIS HELPS!!