What phenomenon occurs after mass extinction?

What rule is used to determine how many covalent bonds an element can form? a. the number of covalent bonds is equal to six c the number of covalent bonds is equal to five minus the group number plus the group number b. the number of covalent bonds is equal to eight d. none of the above minus the group number select the best answer from the choices provided

Anitrogen atom and an oxygen atom combine chemically to form nitric oxide. what is nitric oxide?

Explain what happened when the storm surges from hurricanes reached the gulf coast