Question

A student thinks that the more protons an atom has, the more reactive it will be. Which will best disprove this student's idea?

Compare the reactivities of lithium (Li) and krypton (Kr).
Note that rubidium has 48 neutrons.
Compare the number of protons in cesium (Ce) and xenon (Xe).
Count the number of neutrons in an atom of helium.

Answer 1

I'd have to say that the best choice of the ones listed above would be the first one.

Answer 2

Compare the reactivities of lithium (Li) and Krypton (Kr)

Step-by-step explanation:

Lithium has an atomic number of 3 while krypton has an atomic number of 36. Note that atomic number is the number of protons present in an atom. It can be deduced from the above that krypton has more protons than lithium however krypton is found in the group zero of the periodic table and thus a noble gas. One of the properties of noble gases/group zero elements is that they have low reactivity because of there octet configuration/completely filled outermost shell.

However, lithium on the other hand is a member of group 1 (called alkali metals) in the periodic table. Group 1 elements are highly reactive (there members are some of the most reactive metals) because they have just one electron in there outermost shell which can be easily donated to achieve duplet/octet configuration.

Hence, Lithium (Li) with 3 protons is more reactive than krypton (Kr) with 36 protons hence disputing the student's idea.