How many molecules are there in 150 grams of C12H22O11

Structure of the atoms: discovery of the nucleus in 1909i need answering all of these questions

Which is an example of a reversible physical change?

Equal numbers of moles of he(g), ar(g), and ne(g) are placed in a glass vessel at room temperature. if the vessel has a pinhole-sized leak, which of the following will be true regarding the relative values of the partial pressures of the gases remaining in the vessel after some of the gas mixture has effused?