Agroup of electrons revolving around a nucleus forms an electron

Apiece of copper has a temperature of 75.6 0c. when the metal is placed in 100.0 grams of water at 19.1 0c, the temperature rises by 5.5 0c. what is the mass of the metal?

If a solution contains 3 moles/liter of sodium chloride (nacl, made of sodium ions and chloride ions), what is the osmolarity of this solution

Which scientists contributed to the determination of how cfcs in clouds in the upper atmosphere could destroy ozone molecules