`37.D.6.10^23` nguyên tử
`38.B.4,5.10^23` nguyên tử
`39.A.1,5.10^23` nguyên tử
`40.C.2,5mol`
`41.D.1,25mol`
`42.C.0,4mol`
`43.B.0,25mol`
`44.A.0,5mol`
`45.D.12.10^24` nguyên tử
`46.C.30.10^23`
`47.C.1,7.10^21` nguyên tử
`48.C.160gam`
`49.B.3,6.10^23` nguyên tử
`50.C.1,2004.10^23`
`51.C.4,6.10^23`
`52.B.9.10^23;1,5.10^23;9.10^23;0,6.10^23`
