Answer:
16 percent
Explanation:
Just answered the question
The first option, collapsed in on itself.
The star's core mass becomes so dense that the resulting gravity implodes the star.
Interesting enough, the third option is kindof true too...some large and tenacious black holes that absorb other stars will form incredibly bright accretion disks around their perimeter before filling absorbing the star.
Answer:

Explanation:
Balanced equation: CO(g) + H₂O(g) ⟶ CO₂(g) + H₂(g)
We can calculate the enthalpy change of a reaction by using the enthalpies of formation of reactants and products

(a) Enthalpies of formation of reactants and products

(b) Total enthalpies of reactants and products

(c) Enthalpy of reaction
I think this is it
Cd(HCO3)2---->CdCO3+H2O+CO2
Sorry if this is wrong