chemistry

At 1 atmosphere of pressure, 25.0 grams of a compound at its boiling point is converted to a gas by the addition of 8,180 calories. What is the heat of vaporization for this compound, in calories per gram?

A. 25.0 cal/g

*B. 327 cal/g 

C. 540 cal/g

D. 8,140 cal/g

Which substance can be decomposed chemically?

A. CaO and Ca

B. MgO and Mg

C. CO and Co

*D. CaO and MgO 

The particles of a substance are arranged in a definite shape geometric pattern and are constantly vibrating. This substance can be in 

*A. The solid phase, only 

B. The liquid phase, only

C. Either the liquid or the solid phase

D. Neither the liquid or the solid phase