which of the following is valence shell for the elements of second period of the mordern periodic table M shell K shell L shell N shell

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 conclusion can you draw from this experiment about the components of the black ink?

What are the coefficients to balance the following equation? ba+br2=babr2