Need help too please I would really appreciate it

You have a sample of a metal, the sample is exactly 6.02 x 1023atom, if the sample has a mass 55.85 what metal is your sample made of?

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?

The combustion of methane, ch4, releases 890.4kj/mol. that is, when one mole of methane is burned,890.4 kj are given off to the surroundings. this meansthat the products have 890.4 kj less than the reactants. thus, ah for the reaction = - 890.4 kj. a negative symbolforah indicates an exothermic reaction. ch (g) + 20 (g)> co2 (g) + 2 h0 (1); ah = - 890.4 kga) how much energy is given off when 2.00 mol of ch, are burned? b) how much energy is released when 22.4g of ch. areburned?