Calculate HRXN for the reaction: CaO(s)+CO2(g)CaCO3(s). Use the following reactions and given H's.
Ca(s)+CO2(g)+1/2 O2(g)--CaCO3(s) H=-812.8kJ
2 Ca(s)+O2(g)--2CaO(s) H=-1269.8kJ
Show work.

Explain which group an element with the electron configuration 1s2 2s2 2p6 3s2 3p6 3d1 4s2 belongs to.

Ill give brainiestif one neutron initiates a fission event that produces two neutrons in the products, how many new reactions can now be initiated? if each of the neutrons produced in the first fission event then initiates a fission event that produces one neutron in the products, how many new reactions can now be initiated by each neutron? how many neutrons in total were produced by the two fission events described?

Which statement is true about this reaction? 14n+1h 15o it is a practical source of energy on earth. it occurs only outside the solar system. its product is heavier than each of its reactants. it shows the critical mass of an element.