What do scientists look at in the ice to figure out the earth's atmosphere and temperature?

What does the cell nucleus do or, how does it function?

Achemist 16 drop copper metal from copper chloride solution. the chemist place is 0.50 g of aluminum foil in a solution containing 0.75 g of copper (ii) chloride. a single replacement reaction takes place. which statement explains the maximum amount of copper that the chemist can extract using this reaction?

Calculate the number of kilojoules to warm 125 g of iron from 23.5°c to 78.0°c.