What is heat of vaporization? It is the heat required to change a substances temperature by 1°C,
It is the heat required to change a gram of substance from a solid to a liquid.
it is the heat required to change a substance from a solid buy to a vas.
It is the heat required to change a gram of substance from a liquid to a gps.
it is the heat required to separate one substance into two substances,
OD

Explanation:

It is the heat required to change a gram of substance from a liquid to a gas.

b

explanation:

mitosis

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.