PLEASE HELP! 20 g of copper was heated from 50°C to 90°C. How much energy was used to heat Cu? (Specific heat capacity of Cu is 0.385 J/g °C)

What relationship exists between an enzyme and a catalyst?

When a beta particle is emitted, the mass number of the nucleus a. decreases by one b. increases by one c. remains the same d. decreases by two

To prevent the presence of air, noble gases are placed over highly reactive chemicals to act as inert "blanketing" gases. a chemical engineer places a mixture of noble gases consisting of 4.37 g of he, 13.36 g of ne, and 36.65 g of kr in a piston-cylinder assembly at stp. calculate the partial pressure in torr of kr.