How do you figure out unit conversions?

Particle model to predict what will happen if a sharp object creates a hole in the soccer ball

Acalorimeter is to be calibrated: 51.203 g of water at 55.2 degree c is added to a calorimeter containing 49.783 g of water at 23.5c. after stirring and waiting for the system to equilibrate, the final temperature reached is 37.6 degree c. specific heat capacity of water (s = 4.18 j/g∙degree c). calculate the calorimeter constant. (smδt)warm water = -[(smδt)cold water + (calorimeterδtcold water)]

On the periodic table, elements are arranged by which of the following. a. mass numbers. b. increasing atomic number. c. alphabetical order. or d. density