A tea bag in a cup of hot water can be a simple model of a cell. Water moves into the tea bag and substances in the tea leaves move out through a thin layer of material. What does the thin material that holds the tea leaves represent?

What semimetal can form four single covalent bonds.

Harvey kept a balloon with a volume of 348 milliliters at 25.0˚c inside a freezer for a night.  when he took it out, its new volume was 322 milliliters, but its pressure was the same.  if the final temperature of the balloon is the same as the freezer’s, what is the temperature of the freezer? the temperature of the freezer is  kelvins.

What is the maximum amount of al2(so4)3 which could be formed from 15.84 g of al and 12.89 g of cuso4?