Answer: a) 3.85 days
b) 10.54 days
Explanation:-
Expression for rate law for first order kinetics is given by:

where,
k = rate constant = ?
t = time taken for decomposition = 3 days
a = let initial amount of the reactant = 100 g
a - x = amount left after decay process = 
First we have to calculate the rate constant, we use the formula :
Now put all the given values in above equation, we get


a) Half-life of radon-222:


Thus half-life of radon-222 is 3.85 days.
b) Time taken for the sample to decay to 15% of its original amount:
where,
k = rate constant = 
t = time taken for decomposition = ?
a = let initial amount of the reactant = 100 g
a - x = amount left after decay process = 


Thus it will take 10.54 days for the sample to decay to 15% of its original amount.
Answer:
Some examples of things that stick together include clothes after they were in the dryer because a charge builds up on the objects, causing them to attract to each other. Things that don't stick together may include two neutral objects, like two pieces of neutral paper. ... If they repel, then they are the same charge.
Explanation:
The government should put it support in a combination of sources, as no
source in the present can fully provide all energy requirements.
Answer:
Boyle's Law

Explanation:
Given that:
<u><em>initially:</em></u>
pressure of gas, 
volume of gas, 
<em><u>finally:</u></em>
pressure of gas, 
volume of gas, 
<u>To solve for final volume</u>
<em>According to Avogadro’s law the volume of an ideal gas is directly proportional to the no. of moles of the gas under a constant temperature and pressure.</em>
<em>According to the Charles' law, at constant pressure the volume of a given mass of an ideal gas is directly proportional to its temperature.</em>
But here we have a change in the pressure of the Gas so we cannot apply Avogadro’s law and Charles' law.
Here nothing is said about the temperature, so we consider the Boyle's Law which states that <em>at constant temperature the volume of a given mass of an ideal gas is inversely proportional to its pressure.</em>
Mathematically:



Explanation:
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