Write the empirical formula of at least four binary ionic compounds that could be formed from the following ions: Ca^2+, Fe^2+, Cl^-, O^2-

Yes, endothermic means it turns cold. and some chemical changes include change of tempature.

Afraidsugar lol it’s the third one

Small amounts of matter are converted intolarge amounts of energy occurs in both fusion and fission reactions. they are nuclear reactions where a change in the identity or characteristics of an atomic nucleus results when it is bombarded with an energetic particle, as in fission, fusion, or radioactive decay.