Determine the mass of 4.25x10^26 formula units of barium hydroxide

As you move from right to left on the periodic table the atomic radius fill in the blank

What human activity increases beach erosion?

1) which of the following is the best example of a physical change? a) sugar dissolving in tea b) firefly glowing 2) in the combustion of ethane, what is/are the reactants? c2h6 + o2 ==> co2 + h2o a) c2h6 and o2 b) co2 and c2h6