What is a physical change?
new substance
no new substance
both substances
neither substance

What is the value of the standard enthalpy of formation of an element in its most stable form?

Rank the following four acids in order of increasing bronsted acidity : h2f+ , ch3oh, (ch3)2oh+ , ch3sh2+

If a straight-chain hydrocarbon is a gas at room temperature, how many carbon atoms will it have? a. 6 carbon atoms b. 12 carbon atoms c. 24 carbon atoms d. 3 carbon atoms