Describe how physical properties can be used to identify unknown materials

Each element has a unique set of physical properties, such as density, melting point, and boiling point that can be used to identify them.

Physical properties can be used to identify an unknown element because each element has a unique set of physical properties, such as density, melting point, and boiling point. These are intensive physical properties which do not depend on the amount of substance.

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.

definition

                    entropy is a measure of the randomness or the extent of disorder of a chemical process.

                      enthalpy is a measure of the heat change of a reaction occurring at a constant pressure.

measurement units:

                        entropy is measured in joule per kelvin (jk⁻¹)   whereas enthalpy is measured in joule per mole (jmol⁻¹)

requirements:

                            entropy has no requirements or limits, and its change is measured by the division between the heat change of the chemical process and the temperature.

                              in contrast, enthalpy can only be related to the heat change of the reaction under standard conditions.