a flask holds five times as many moles of N2 as O2. If the total pressure in the jar is 18 atm, what is the pressure exerted by oxygen?

What are the 4 phases of matter in order of increasing engery content?

Sally is making a model of a magnesium atom with an atomic mass number of 24 for her chemistry class. she has foam balls for the protons, neutrons, and electrons. she has added 6 neutrons to her model so far. how many more neutrons does she need to add to complete her neutral atom of magnesium?

Calculate the number of kilojoules to warm 125 g of iron from 23.5°c to 78.0°c.