Answer:
A.
Explanation:
While solar power does produce carbon dioxide emissions in the manufacturing processes required to produce panels and batteries, it does not produce CO2 while converting solar energy to electrical energy.
I think it’s number 5 and number 9 hopes this helps.
Answer:
fluoride ion with a charge of -1
Explanation:
If a fluorine atom gains an electron, it becomes a fluoride ion with an electric charge of -1.
N=m(g)/m.wt
n=85/12(1)+16(2) =1.93 moles
The much of the sample that would remain unchanged after 140 seconds is 2.813 g
Explanation
Half life is time taken for the quantity to reduce to half its original value.
if the half life for Scandium is 35 sec, then the number of half life in 140 seconds
=140 sec/ 35 s = 4 half life
Therefore 45 g after first half life = 45 x1/2 =22.5 g
22.5 g after second half life = 22.5 x 1/2 =11.25 g
11.25 g after third half life = 11.25 x 1/2 = 5.625 g
5.625 after fourth half life = 5.625 x 1/2 = 2.813
therefore 2.813 g of Scandium 47 remains unchanged.
