Human activities can have an impact on Earth's systems. Which Earth system is most affected when factories burn harmful chemicals and release substances into the air?

Agraduated cylinder contains 63.0 ml of water. a piece of gold, which has a density of 19.3 g/ cm3, is added to the water and the volume goes up to 64.5 ml. calculate the mass in grams of the gold that was added to the water. explain how you got your answer.

What would be the radius of the earth if it had its actual mass but had the density of nuclei? express your answer to two significant figures and include the appropriate units.

What electron configurations do atoms usually achieve by sharing electrons to form covalent bonds?