In your own words What is the average atomic mass of an element?

If a planet rotates 360 degrees during a 24 hour time period, what does that tell us about the planet? a. the middle of the planet is in darkness b. the seasons on the planet vary every day. c. the planet runs on a 12-hour time clock. d. the temperature on the planet varies daily.

If 90.0 grams of ethane reacted with excess chlorine,how many grams of dicarbon hexachloride would form

Why do cells appear different in distilled water than they do in 10% salt water?