The density for iron is 7.874 g/cm3.What would be the mass of a 25cm3 piece of iron?

Which statement justifies that phosphine (ph3) is a polar molecule?

Agas at 155 kpa and standard temperature has an initial volume of 1.00 l. the pressure of the gas rises to 500 kpa as the temperature also rises to 135°c. what is the new volume? 2.16 l 0.463 l 0.207 l 4.82 l

The mass of a neutron is equal to the mass of a proton plus the mass of an electron. true or false false true