Find the ΔHr0 for the reaction of one mole of solid magnesium carbonate that decomposes into one mole of solid magnesium oxide and one mole of carbon dioxide gas.

MgCO3(s)→MgO(s) + CO2(g)

Answer choice:
A.)ΔHr0= -45.3kJ
B.)ΔHr0= +105.8kJ
C.)ΔHr0= +125.7kJ
D.)ΔHr0= +117.0kJ
E.)ΔHr0= -140.0kJ

Several kinds of bears are found on earth. most bears are brown or black, but one type of bear, the polar bear, is white. what process led to this difference in fur color? explain your answer.

May someone me with these science questions

Which of the following is the correct definition of chemical energy? a. energy an object has because of its motion or position b. energy resulting from the flow of charged particles, such as electrons or ions c. energy produced from the splitting of atoms d. energy stored in chemical bonds of molecules