Of the eighteen elements in the fourth period, whicha. has the largest atomic radius? b. has the smallest first ionization energy? c. has the largest electron affinity? d. has the lowest electronegativity? e. has the highest electronegativity? f. are electrical semiconductors? g. is one of the least reactive elements?

(A) potassium

(B) potassium

(C) bromine

(D) potassium

(E) bromine

(F) germanium and arsenic

(G) krypton

Explanation

(A) potassium has the largest atomic radius because atomic radius is one-half the distance between the nuclei of two atom.

(B) ionization energy is the energy required to remove an electron from a neutral atom in its gaseous phase. Potassium has the smallest first ionization energy because it has just one electron. This will make it easier to be remove during chemical combination.

(C) bromine has the largest electron affinity. Electron affinity is the ability of an element to attract and accept an electron. Bromine has 7 electron in its outer-most shell. Hence will easily attract one electron to have a stable electronic configuration.

(D) electronegativity is the ability of an element to attract and bind with electron. pottasium has the lowest electronegativity because it has just one electron which is readily available for chemical combination. So it hardly attracts electron.

(E) bromine has the highest electronegativity because it has seven (7) electrons and need just one electron to have a stable electronic configuration.

(F) this are semiconductor, they have properties in between.

(G) krypton is a noble gas, it does not react because it has a complete electronic configuration.