Based on the figure below, what do the elements of a group (family) have
in common

As a part of an experiment a student burns propane to produce carbon dioxide and water she remembers that she must follow the law conservation of matter when writing a balanced chemical equation which of these equation adheres to the law of conservation of matter

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 formula for the compound dinitrogen pentoxide? a. n4o5 b. n5o4 c. n4o6 d. n5o2 e. n2o5