Which reaction can be used to calculate the enthalpy of formation of a substance? 2 (g)→ (g)+.5 2 (g)
(g)+.5 2 (g)→2 (g)
(g)+2 (g)→3 (g)
2 (g)+.5 2 (g)→2 (l)

How is 0.00235 expressed in proper scientific notation? a. 2.35 × 10-3 b. 0.235 × 10-2 c. 2.35 d. 2.35 × 103

What are the charges of the subatomic particles by choosing the answer from the drop down menu. protons have a (+1,0,or-1). (protons, neutrons, electrons) have a 0 charge. 3.) electrons have a (+1,0,-1)

The valence of aluminum is +3, and the valence of the chlorine is -1. the formula fir the aluminum chloride is correctly written as