Answer:
Explanation:
The reactivity of elements in the periodic table is based on the number of electrons in there outermost shell. Elements (metals) that have few electrons in there outermost shell are highly reactive because it is easier to lose fewer number of electrons (in the outermost shell during a reaction) than to lose more electrons in the outermost shell - thus metals that have one electron in there outermost shell are most reactive and are more reactive than those that have two electrons in there outermost shell. Hence, metals in group 1 are the most reactive metals because they all have one electron in there outermost shell.
Non-metals that have fewer electrons to complete there octet configuration are highly reactive because it is easier to gain fewer number of electrons (in the outermost shell during a reaction) than to gain more number of electrons - thus nonmetals that have seven electrons in there outermost shell are more reactive than nonmetals that have six electrons in there outermost shell. Hence, nonmetals in group 17 are the most reactive nonmetals because they contain seven electrons and have just one electron left to complete there octet configuration.
D. all of the above are in the atmosphere
Physical: The chemist could try to bend it to find out how malleable it is. He could also try to pull it into wires to find out how ductile it is.
Chemical: The chemist could put the metal into contact with other substances to get an idea of how reactive it is, and he could try to burn it and find out how flammable it is.