Answer:
D.
Explanation:
It would not be gain because it would say +6 instead of -2. Having a -2 charge means it wants to loose 2 electrons so it can form a full shell of 8 electrons. It wants to be inert (stable).
- Hope that helps! Please let me know if you need further explanation.
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.
Answer:
215 amu
Explanation:
In the reactants:
There is 1 iron atom, 3 chlorine atoms, 6 hydrogen atoms and 3 oxygen atoms:
- Fe: 56 × 1 = 56
- Cl: 35 × 3 = 105
- H: 1 × 6 = 6
- O: 16 × 3 = 48
56 + 105 + 6 + 48 = 215 amu
Hope this helps!
