The spacing is 14.4 nm (nanometers).
It is 14.4 * 10^(-9) m
And 1 mm = 1 * 10^(-3) m
14.4 nm * 105 = 1,512 nm = 1.512 micrometers = 0.001512 mm
Or : 1.512 * 10^(-3) mm
Answer: The total width of crystal is 0.001512 mm.
The formula you need is: heat= specific heat x mass x ΔT
specific heat= 0.46 j/g-C
mass= 100.0 grams
ΔT= 40.2 - 15.0= 25.2C
heat= (0.46) x (100.0) x (25.2)= 1159.2 joules or 1200 joules (rounded off)
