Is burning a physical change or a chemical change? Justify your answer!

A chemical change occurs whenever matter changes into an entirely different substance with different chemical properties. Burning is an example of a chemical change.

Explanation:

Chemical Change

Explanation:

Burning of an object is an irreversible process. It cannot be turned back into its original reactant. Physical change would be something like ice melting. You could freeze the water back into ice, therefore reversible.

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.