Two cups of the same size are filled to the brim with clear liquids. cup a holds water. cup b contains alcohol. your teacher challenges you to figure out which cup holds water. because of your great science knowledge, you know that all substances have their own special properties. you and your lab partner add an ice cube to each cup. the ice floats in one liquid. you predict it is water. and the ice sinks in the other liquid. you predict that liquid is alcohol. what type of property of matter did you use to identify the liquids?

They used density, density is the degree of compactness of a substance.

explanation:

metals have excess of electrons whereas non-metals have deficiency of electrons. thus, in order to gain stability metals easily donate their electrons to the non-metals.

for example, electronic configuration of sodium is and electronic configuration of phosphorous is .

when a phosphorous atom and sodium atom combine together then sodium will donate is extra one electron to the phosphorous atom. as a result there will be formation of ionic bond between sodium and phosphorous.

the reaction will be as follows.

there, are three sodium sodium atoms and each of them will donate its one extra electron to phosphorous atom. thus, the sub-shell of phosphorous gets completely filled.  

thus, we can conclude that electrons are transferred from atoms of sodium to atoms of phosphorous. this transfer makes the sodium atoms donate one electron and the phosphorous atoms to gain one electron. as a result, the sodium and phosphorus atoms strongly attract each other.