A cylinder contains water to a level of 15.5. 20.0 grams of copper is dropped in. What will be the new height of the water?

Estimate the molar mass of the gas that effuses at 1.6 times the effusion rate of carbon dioxide.

Can someone me out on this question for my national 5 chemistry homework

Select the statement that describe chemical properties a. antacid tablets neutralize stomach acid b. helium is the lightest monatomic element c. water freezes at 0 celsius d. mercury is liquid at room temperature