How do the properties of magnets allow them to be useful to society?

What is the molar mass of a gas that has density of 2.054 g/l

Draw the lewis dot structure for each of the following polyatomic ions

What is the binding energy of a nucleus that has a mass defect of 5.81*10-^29 kg a 5.23*10-^12 j b 3.15* 10^12 j c 1.57*10-3 j d 9.44*10^20 j