Answer:
Both involve drilling into the earth and can cause environmental degradation.
Explanation:
I think I have done a question like this before and i'm pretty sure your answer would be the 2nd one 1s22s22p4. I'm not 100% sure but try it at least.
Question 17: answer:The solute is the drink crystals and the solvent is the water…
I wish I am correct
Answer:
320 g
Step-by-step explanation:
The half-life of Co-63 (5.3 yr) is the time it takes for half of it to decay.
After one half-life, half (50 %) of the original amount will remain.
After a second half-life, half of that amount (25 %) will remain, and so on.
We can construct a table as follows:
No. of Fraction Mass
half-lives t/yr Remaining Remaining/g
0 0 1
1 5.3 ½
2 10.6 ¼
3 15.9 ⅛ 40.0
4 21.2 ¹/₁₆
We see that 40.0 g remain after three half-lives.
This is one-eighth of the original mass.
The mass of the original sample was 8 × 40 g = 320 g
