Why can graphite be used as a lubricant

If the density of water is 1.0 g/cm3, which of these materials would float in water, based on their densities? check all that apply. aluminum cork iron lead wax

What do electromagnetic waves carry? how are they produced through which media can they move? where do they transfer energy? what do they not transfer? what do mechanical waves carry? how are they produced? through which media can they move? where do they transfer energy? what do they not transfer?

What is the equation fort the alkaline zinc/manganese dioxide cell. a) anode b)cathode c)overall equations.