How many moles are present in 13.9 grams of Ba(NO3)2?

Which metal exist in liquid state and can be cut with knife ?

Some animals that try to adapt to climate changes eventually die due to starvation, as climate change alters the web.

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