Answer: half life
Explanation: Radioactive decay follows first order kinetics and the time required for the decay of a radioactive material is calculated as follows:

t= time required
k= disintegration constant
x= amount of substance left after time t
a= initial amount of substance
when one half of the sample is decayed, one half of the sample remains and t can be represented as 
at
, 


Answer:
Calculate the pH of a buffer prepared by mixing 30.0 mL of 0.10 M acetic acid and 40.0 mL of 0.10 M sodium acetate.
Answer:
a) After helping our partner, we should immediately report the incident to the lab manager or any person in charge of the emergencies occurring in the lab.
b) We should have a copy of the Material Safety Data Sheet to give to the responders. This is because the responder can identify what materials were being used by the person ans what other security measures need to be taken.
Answer:
m = E × Q
And Q = I × t
m = E × I × t
Where m = mass in grams
Q = quantity of electricity in coulomb
I = current in ampere
t = time in seconds
E = electrochemical equivalent of the substance
Explanation: