8,766 hours is your answer :)
Answer:
The half life is 
Explanation:
The half life of a first order reaction is mathematically represented as
Substituting
for the rate constant

Answer: The space occupied by the gas at 400 torr and
is 250 mL.
Explanation:
Given:
= 250 mL,
= 800 torr, 
,
= 400 torr, 
Formula used is as follows.

Substitute the values into above formula as follows.

Thus, we can conclude that space occupied by the gas at 400 torr and
is 250 mL.
A spund waves can travel through ALMOST everything.