Carbon dioxide is a gaseous molecule made up of the elements, C and O. Each mole of carbon dioxide has one mole C and two mole oxygen atoms.
Molar mass of carbon dioxide (
)=
Percentage by mass of carbon = 
Percentage by mass of oxygen = 
Therefore C is 27.3 % and O is 72.7 % by mass in 1 mol CO
The energy change if 84.0 g of CaO react with excess water is 98KJ of heat is released.
calculation
heat = number of moles x delta H
delta H = - 65.2 Kj/mol
first find the number of moles of CaO reacted
moles = mass/molar mass
the molar mass of CaO = 40 + 16= 56 g/mol
mass = 84 g
moles therefore = 84 g/56 g/mol =1.5 moles
Heat is therefore = 1.5 moles x -65.2 = - 97.8 Kj = -98 Kj
since sign is negative the energy is released
Radiation
hope that helped!
Displacement is the distance and direction of an object's change in position from the starting.
Hence option B is correct.
Hope this helps!
