When applying heat to a substance changes the form, but not the identity of the substance, this is evidence of:
a chemical change
a physical change
no change
an anthropomorphic change

This is the evidence of physical change.

Explanation:

When the substance is heated, its form is changed but identity remain the same, it is then a physical change. In physical change substance can only change their phases but not lose the identity. For example it may change its state from solid to liquid and liquid to gas.

Physical change:

The changes that occur only due to change in shape or form but their chemical or internal composition remain unchanged.

These changes were reversible.

They have same chemical property.

These changes can be observed with naked eye.

Example s:

Water converting to Ice .

Water converting to gas.

In this water molecule remain the same only they rearrange themselves that change its state of mater not composition.

Chemical change:

The changes, that occur due to change in the composition of a substance and result in a different compound is known as chemical change.

These changes are irreversible .

These changes occur due to chemical reactions .

These may not be observed with naked eye .

Examples:

combustion of fuel or wood: that oil or wood convert into energy, CO2 and ash in case of wood .

Boiling of egg: that change the chemical composition of protein in the egg

d.) the average kinetic energy of the gas particles is greater in container b because its particles move faster.

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.