Classify each of the following statements as a hypothesis, a law, or a theory. (a) Beethoven’s contribution to music would have been much greater if he had married. (b) An autumn leaf gravitates toward the ground
because there is an attractive force between the leaf
and Earth. (c) All matter is composed of very small
particles called atoms

c- cold periods in earth's history during which glaciers covered much of the surface.

explanation:

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.