I believe it might be c I might wrong
Answer:
Final temperature of the gas is 576
.
Explanation:
As the amount of gas and pressure of the gas remains constant therefore in accordance with Charles's law:

where
and
are volume of gas at
and
temperature (in kelvin scale) respectively.
Here
,
and 
So
849 K = (849-273)
= 576 
So final temperature of the gas is 576
.
Answer: the minimum amount of energy required to break bonds and start a chemical reaction
Explanation: got a 100% on the quick check
Answer:
N = n× l
N = number of entities
n= moles
l = Avogadro's constant = 6.023 × 10^23
3.01 × 10^ 23 = n * 6.023 × 10^23
n = 3.01 × 10^23/6.023 × 10^23
n= 0.5moles
Molar mass = mass/ number of moles
Molar mass = 56
mass = 56 × 0.5
= 28g
Hope this helps.