When an oxygen atom forms an ion, it gains two electrons. What is the electrical charge of the oxygen ion?

A.

+2

B.

-1

C.

+1

D.

-2

Which of the following is correct concerning Hess's law? A. The change of enthalpy of a reaction can be found be subtracting the enthalpy of the products from the enthalpy of the reactants. B.

How many moles of carbon are in 43.65 grams of carbon?

A large rift valley can be found along the east coast of Africa. It has been slowly widening over time, and it is now wide enough to contain many large lakes. Which of these best explains the slow widening of this rift valley over time? A.

Determine whether each molecule is polar or nonpolar. a. scl2 b. scl4 c. brcl5

Which statement best describes the process that the diagrams show? A solid loses kinetic energy to become a liquid and then becomes a gas A solid gains kinetic energy to become a liquid and then becomes a gas, Agas loses kinetic energy to become a

The spines and thick wavy cuticle on a cactus are both what

What type of chemical process is used to create perfume?

Which of the following is a polyatomic ion? O A. HCI O B. Na O C. PO, O D. 52

What are the cations and anions for V2 (CO3) 3

If you were asked to convert 4.2 x 1022 atoms of aluminum to moles, which of the following should you use for the conversion?