Since protons are postive and neutrons are neutral. Then it is postive.
58.7 %
Please correct me if I’m wrong. :)
Answer: 66
Explanation: To find the mass number you would have to add the number of protons and the number of neutrons.
Answer:
b. 1.5 atm.
Explanation:
Hello!
In this case, since the undergoing chemical reaction suggests that two moles of A react with one moles of B to produce two moles of C, for the final pressure we can write:

Now, if we introduce the stoichiometry, and the change in the pressure
we can write:

Nevertheless, since the reaction goes to completion, all A is consumed and there is a leftover of B, and that consumed A is:

Thus, the final pressure is:

Therefore the answer is b. 1.5 atm.
Best regards!
We are given the following equation:
y = y0 e^-0.0001216 t
where y = 1/5 y0, y0 is the original amount
So solving for time t:
1/5 y0= y0 e^-0.0001216 t
t = 13,235.51 years
So the human died about 13235.5 years ago