physical
Sodium chloride is a chemical compound (NaCl), not a property.
Sodium is a chemical element, not a change.
Its a physical
Slicing a pellet of sodium in half is a physical change because it does not alter the chemical composition of the sodium. The sodium is still sodium before and after slicing, just in smaller pieces.
Sodium and bromine are chemical elements, not properties; the chemical reaction between sodium and bromine is a chemical process, not a property.
chemical
When sodium melts, it undergoes a physical change. This is because the change in state from solid to liquid does not alter the chemical composition of the sodium itself. It remains as sodium in both the solid and liquid states.
This is a chemical reaction, a chemical change.
tae
Dissolving sodium chloride in water is a physical change because the chemical composition of sodium chloride remains the same. The sodium and chloride ions are simply dispersed throughout the water, but they can still be recovered by evaporating the water.
Dissolving sodium carbonate in water is a physical change, not a chemical change. This is because the chemical composition of sodium carbonate remains the same before and after dissolving.
Melting is a physical process; reaction with sodium is a chemical process.