Question

This chart lists four elements from the periodic table.

Atoms from which two elements would form ionic bonds?
a. calcium and gold. b. gold and argon. c. argon and iodine.  d. iodine and calcium

Answer 1

Iodine and Calcium is the correct answer

Answer 2

Answer: d. iodine and calcium

Step-by-step explanation: Ionic bonds are formed by transfer of electrons between metal and non metals.

Covalent bonds are formed by sharing of electrons between non metals

Electronic configuration of calcium:

`[Ca]=[Ar]4s^2`

Calcium atom will lose two electron to gain noble gas configuration and form calcium cation with +2 charge.

`[Ca^(2+)]={Ar]`

Electronic configuration of iodine:

`[I]=[Kr]4d^(10)5s^25p^5`

Iodine atom will gain one electron to gain noble gas configuration and form iodide ion with -1 charge.

`[I^-]=[Kr]4d^(10)5s^25p^6`

In calcium iodide the one electron from calcium metal gets transferred to iodine atom and thus form an ionic bond to give
`CaI_2`