Answer:
Age of the ancient wood object is 11460 years.
Explanation:
We know that half-life for carbon-14 is 5730 years. That means the activity of the sample will decrease to half every 5730 years.
Now we construct the following table:
activity (counts/min) age of the wooden object
40 0
20 5730
10 11460
Answer:
= 17% (v/v)
Explanation:
% by Volume = (Volume HCl / Volume of Solution)100%
= 15ml/(75ml + 15ml) x 100% = 16.66666667% (calculator answer)
= 17% (v/v) 2 sig figs. based on volume values given.
B. 6.45 mol F2
The mole ratio here is 3 mol F2 for every 1 mol S. Multiply 2.15 mol S by 3 to get the mol of F2 needed.
Answer:
Coefficient of
is more than 4
Explanation:
Oxidation: 
- Balance charge:
......(1)
Reduction: 
- Balance Cr:

- Balance O and H in acidic medium:

- Balance charge:
.......(2)
gives balanced equation:

So coefficient of
is more than 4