How much cesium (half-life = 2 years) would remain from a 10 g sample after 2 years?

Order the following from smallest to largest atom, electron, quark, proton, neutron, molecule, nucleus

When an object falls through the air and encounters air resistance its overall speed will be than if it had not encountered air resistance? (one word answer)

Consider the reaction: n2(g) + o2(g) ? 2no(g) kc = 0.10 at 2000oc starting with initial concentrations of 0.040 mol/l of n2 and 0.040 mol/l of o2, calculate the equilibrium concentration of no in mol/l how would this be done?