What is an endothermic reaction

An endothermic reaction is one which results in a net decrease in temperature because it absorbs heat from the surroundings and stores the energy in the bonds formed in the reaction.

1.43 x 10^-11 j the guy commented the awnser just making sure u see it .

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

that's it!

if you need further assistance, let me know: )

~ trueboss72