Need !
a dry beaker has a mass of 55.0 g. when 50.0 ml of water is added to the beaker, the mass of the water and the beaker is 105.0 g. what is the density of the water?

In a sample of oxygen gas at room temperature, the average kinetic energy of all the balls stays constant. which postulate of kinetic molecular theory best explains how this is possible? a. attractive forces between gas particles are negligible because the particles of an ideal gas are moving so quickly. b. collisions between gas particles are elastic; there is no net gain or loss of kinetic energy. c. gases consist of a large number of small particles, with a lot of space between the particles. d. gas particles are in constant, random motion, and higher kinetic energy means faster movement.

Each of the following compounds contains a metal that can exhibit more than one ionic charge. provide systematic names for each of these compounds. (a) cr(clo3)6 (b) mo(cn)6 (c) cr2(so3)3 (d) v(clo2)2 (e) v(cn)5 (f) os(clo2)4

Can someone me with questions 15 to 17 plz.