Sort the examples based on whether they describe a physical change or a chemical reaction?
growth of a seed into
a seedling/wax melting from
applied heat/making caramel by
burning sugar/tarnishing of silver/grinding wheat to
make flour/adding copper with gold
to make jewelry

A change in which chemical composition of the substance changes is known as a chemical change and said to have undergone a chemical reaction and a change in which only the physical properties of a substance change is known as a physical change.

Processes like cutting, grinding, phase change (melting, freezing, boiling) are all physical changes.

Processes like corrosion, burning are chemical changes.

Physical change:

A seed into seedling

wax melting from applied heat

grinding wheat to make flour

adding copper with gold to make jewelry

In all of the above examples, only the physical properties such as size, shape and phase has changed. hence, these are physical changes.

Chemical reaction occurs in:

making caramel by  burning sugar

tarnishing of silver

A chemically different new product is being formed when substance undergoes a chemical reaction like in the above examples.

the earths atmosphere is made up of nitrogen and oxygen. solids can turn into gasses through a process called sublimation. sublimation is the transition of a substance directly from the solid to the gas phase, without passing through the intermediate liquid phase.

hope this : d