If you heat a mixture, will the mass change? why or why not?

The number to the right of an element's symbol (ex. c-12) identifies the of an isotope.

How many moles of oxygen gas are produced from the decomposition of six moles of potassium chlorate

Which substance—wood or silver—is the better thermal conductor? a thermal conductor is a material that requires very little heat energy to change its temperature. explain your answer.