Answer: Kinetic Energy of the atoms also increases.
Explanation: We are given that the temperature of the gas increases.
Relation between kinetic energy and temperature follows:

where, K = Average Kinetic energy
R = Gas constant
T = Temperature
= Avogadro's number
As seen from the relation above, the Kinetic energy of the gas is directly proportional to the temperature, hence as the temperature increases, kinetic energy of the atom also increases.
The freezing point of water is 0° C. The Celsius (centigrade) scale is based off of water, with the freezing point at 0° and the boiling point at 100°. (Google will probably tell you this in 10 seconds, then you wouldn't have had to wait 7 hours!)
Particle is more than an atom - a particle I beleive implies either a diatomic gas or just a plain old unbonded noble gas atom? hope this helped.
So half life is the time taken for a sample to decay to half its original mass, its a constant and applies to any original mass, it could be 5g or 1kg, it will take the same amount of time for the original mass to half. In this case the half life is 3 days.
After 3 days the sample will be at half its original mass, now 50g.
Now we can treat the 50g as if its a new sample. After another 3 days (6 days in total) there will be half of 50g left, = 25g.
A base and an Acid always react to form a salt and water
So, HCl + NaOH —> NaCl + HOH