Calcium chloride is as an ice-melting compound on sidewalks and city streets. Explain what is happening (use one of the terms-exothermic or endothermic in your explanation).

it's c. elements are placed in rows based on how may valencies electrons have.

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

oxygen, selenium, tellurium, and polonium.

they're all from the same group as sulfur (group 16).