Ultraviolet Rays, Radio Waves, and Gamma Rays.
:)
An old penny rusting, remember you can’t undo a chemical change

<u>b. a positive cation and a negative anion</u>
✏ Anions are negative in nature while cations are positive in nature. Together they come together by an attractive electrostatic force to form an ionic bond.
ʰᵒᵖᵉ ⁱᵗ ʰᵉˡᵖˢ

Mineral composition affects the classification of igneous rock. in simplified classification, igneous to is are classified by the type of feldspar present, by the I type a of feldspar present, or the absence of quartz. in case of neither present, then by the type of iron or magnesium present.
Nothing happens because a physical change only changes the appearance of the substance, whereas a chemical change transforms the substance into something completely different.
i.e. (chemical change) wood + fire = ash
(physical change) wood + axe = smaller pieces of wood