Give the correct symbol for an element or ion that fits each other following descriptions.

Question

Give the correct symbol for an element or ion that fits each other following descriptions.

[J] = noble gas e- configuration

a. a transition metal w/ 5(n-1)d electrons ____Y____

b. the smallest atom in the 5th period ____Xe_______

c. diatomic element in the 4th period _____Br_______

d. an element with configuration [J]ns^2 np^5 ___I______

e. an element with configuration [ J] (n-2)f^14 (n-1)d^10 ns^2 np^2 ____Pb_______

f. a cation isoelectronic with Kr ____Ca_________

g. an anion larger than Br- _______Br_____

h. the most reactive metal _______Fr_______

could you guys please check my answer to see if they are correct.? please let me know which one is wrong and why it is wrong because i want to learn from it.

thanks

Answer 1

a) Please pick an appropriate n. Here n must be greater than 2 (that would have d orbitals) and less then 4 (there are a max of 10 d electrons. Hence n = 3, and 5(n-1) = 10. The element is Zn.

d) I would not pick I, since there are also d-electrons in I. One example is as shown in (e). I would pick Ar.

f) Please understand the problem. Ca has 16 electrons LESS than Kr. The right answer is Rb+ or Sr(2+)

g) "Br" is neither an anion nor larger than Br-. The right answer is I-.

The others are correct.