Why must chemical equations be balanced? question 3 options: to show that sometimes the amounts of atoms vary to represent conservation of energy to represent conservation of mass to make the chemical reaction work as planned

To represent conservation of mass.

Explanation:

As the law given by Antoine Lavoisier which states that " in a chemical reaction, mass before and after the reaction remains the same that is mass remains conserved in a chemical reaction" which is known as Law of Conservation of Mass.

Total mass of the reactants = Total mass of the products

So, in order to represent the conservation of mass chemical equation should always be balanced.

is there multiple choice answers?

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.