Elements are pure substances that cannot be broken down into simpler parts by chemical methods. Each element consists of only one type of atom with the same chemical makeup, size, and mass.
Compounds are formed when atoms of different elements combine to form molecules through chemical bonds. All compounds are molecules, but not all molecules are compounds.
Both elements and compounds are pure chemical substances.
Physical changes, such as melting ice to water, do not alter the substance's chemical composition. In compounds, physical forces may not break down the molecules entirely.
Chemical changes in compounds occur when chemical bonds are created or destroyed, resulting in the formation of new substances. Energy is released or absorbed during these processes.
When elements combine to form compounds, their behaviors change. For instance, sodium (Na) is highly reactive, but when it bonds with chlorine (Cl) to form table salt (NaCl), it becomes non-reactive and edible. Explore more at etutorworld.com.