How many moles of oxygen molecules are there in 24 dm3 of air at r. t.p.? Assume air is 20% oxygen? What mass of sodium hydroxide is there in 35 cm3 of a 2 mol / dm3 solution of sodium hydroxide?
How many oxygen atoms are there in 4.9 g of H2SO4?
plz answer these, it's so important!!

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

Rocks, as they are compressed, begin forming mountains above the earth's surface when two continental plates converge. the continental crust increases in depth as the mountains grow above. the himalayan mountains formed at a convergent plate boundary in this manner. the rocks are smashed together causing them to due to the intense heat and pressure from the colliding plates and eventually forming rock. a) melt; igneous b) layer; sedimentary c) recrystallize; metamorphic d) melt into the earth's interior; metamorphic

Is powdered sports drink ionic or covalent ? 10pts !