What forms the structure called a coral reef

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

Which other elements contain the same number of outer electrons as sodium

Which buffer would be better able to hold a steady ph on the addition of strong acid, buffer 1 or buffer 2? explain. buffer 1: a solution containing 0.10 m nh4cl and 1 m nh3. buffer 2: a solution containing 1 m nh4cl and 0.10 m nh3