which of the following is an example of chemical energy being used?

a. battery in a flashlight
b. ice melting
c. riding a bicycle
d. mercury rising in a thermometer

Apackage contains 1.33 lb of ground round. if there’s 29% fat, how many grams of fat are in the round? i got 175 g but the textbook says the answer is 91 g of fat. how?

The density of an unknown gas at 98°c and 740 mmhg is 2.50 g/l. what is the molar mass of the gas with work showed?

How many moles of lead are in 1.50 x 10^12 atoms of lead? could you explain the answer as well and not just give it to me i am refreshing for finals and i need to know how to do it