Answer
Table salt (sodium chloride NaCl) is an ionic compound made up of sodium ions (Na+) and chloride ions (Cl-). We are able to eat the compound table salt, showing that it has different properties from those of its components sodium (Na) (a metal with metallic bonding- positive sodium ions surrounded by a sea of delocalised electrons in a regular lattice arrangement) and chlorine (Cl${_2}$) (a poisonous gas that is a covalent compound).
Work Step by Step
If something has an emergent property, that means a whole entity (e.g NaCl) is observed to have properties its parts do not have on their own (Na and Cl${_2}$). In this case, table salt (NaCl) is a harmless, necessary part of human consumption. It is an ionic compound made up of sodium ions (Na+) and chloride ions (Cl-). NaCl has a high melting and boiling point (of 1474 °F and 2575 °F respectively under standard conditions.)
Sodium is a soft, silvery-white metal. It has a melting point of 207.9°F and a boiling point of 1621.4°F and is part of the Alkali Metals group, which are highly reactive when in contact with water, violently erupting (Na reacts with water to give aqueous sodium hydroxide and hydrogen gas).
Chlorine is a yellow-green toxic gas, with a melting point of -149.8 °F and boiling point of -30.3 °F, has been used on its own as a chemical weapon.
Both sodium and chlorine have very different properties in terms of structure, appearance and melting and boiling point compared to table salt.
