A. the density stays the same unless given an external catalyst
84 divided by 2 = 42.
2 goes into 8 four times, so there would be your 4.
Then 2 goes into 2 one time, and there would be your 2.
You check your answer by multiplying 42 by 2, which would give you, 84.
Answer:
The right answer to this is (b)
Answer: 151 kJ
Explanation:
To calculate the moles :
It is given that:
0.267 moles of 
absorb energy = 40.3 kJ
Thus 1 mole of absorb energy =
Thus the value of 
for the chemical equation given is 151 kJ
Moles =mass/ molar mass of the bromine atom
the molar mass of bromine atom is 79.904g/mol
mass=2.60 x10^2
therefore the moles of bromine atom=
2.60 x10^2g/ 79.904g/mol =3.25gmoles(answer 4)
