What must be part if a quantitative observation?

Determine the mass of fuel required for the expected energy consumption in the united states for the next ten years. energy use per person per year in the united states = 3.5 x 1011joules base calculations on current population of 310,000,000.

An atom of sodium-23 (atomic number = 11) has a positive charge of +1. give this information, how many electrons does it have? how many proteins and neutrons does this atom have

Describe what happens to the molecules as water goes from ice to liquid to vapor. be sure to explain what happens to the temperature during the phase changes.