endothermic means it absorbs energy while exothermic means it releases energy. remember this.
Then that would be 100% all together I believe
It would be Atom 2 because the proton and neutron are both nine and the election is 8 which is -1 to nine <span />
Calcium Floride (Caf2)
Hope this helped =D
Q = mcΔθ
67.5 = m x 0.45 x (28.5 - 21.5)
M = 67.5 / 3.15
= 21.4 g
