I think the correct answer would be the third option. An example of a pure research would be creating synthetic elements to study their properties. Pure research is also known as fundamental or basic research. It has an exploratory nature wherein it is done without any end use in mind. It is mostly out of the curiosity or intuition of a researcher. Most of the study under this type is aiming to advance an existing knowledge by explaining or identifying the relationship of the variables being studied. It is aimed at improving theories in order to the understanding of a specific phenomenon.
Extensive property (like volume and mass), can be measured.
Ionic bond
Na+ has a POSITIVE charge
while Cl- has a NEGATIVE one.
Through ionic bond both form NACL (Salt).
