Which observation illustrates the law of conservation of mass? the c: o mass ratio of a particular compound is the same, regardless of the size or source of the sample. / when 3 g of carbon reacts with 8 g of oxygen, 11 g of carbon dioxide is produced. / the c: o mass ratio of one compound is exactly double that of another compound./ burning 10 g of propane produces twice as much carbon dioxide as burning 5 g of propane.

alkaline metals are lithium, sodium, rubidium, potassium, cesium and francium.

alkali metals have electronegativity from 0.7 to 1, lowest in periodic table of elements, which means that alkali metals (i group in periodic table) has positive oxidation number in compounds.

electronegativity is a chemical property that describes the tendency of an atom to attract a shared pair of electrons towards itself.

alkaline metals (far left in main group) have lowest ionizations energy and easy remove valence electrons,

for example, potassium is the alkali metal and has a single valence electron in the outer electron shell.

electron configuration of potassium is: ₁₉k 1s²2s²2p⁶3s²3p⁶4s¹.

they can not exist alone in nature, because they are very reactive.