Question

electron configuration practice
due date:
chemistry
e. in the space below, write the full (unabbreviated) electron configurations of the following elements:

1. sodium
2. iron
3. bromine
4. barium
5. magnesium

f. in the space below, write the noble gas (abbreviated) electron configurations of the following elements:

1. cobalt
2. chlorine
3. tellurium
4. radium
5. rubidium

g. determine what elements are denoted by the following electron configurations:

1. $1s^22s^22p^63s^23p^4$
2. $1s^22s^22p^63s^23p^64s^23d^{10}4p^65s^1$
3. $kr 5s^24d^{10}5p^3$
4. $xe 6s^2$
5. $rn 7s^2$

Explanation:

Step1: Full config for sodium (Z=11)

$1s^22s^22p^63s^1$

Step2: Full config for iron (Z=26)

$1s^22s^22p^63s^23p^64s^23d^6$

Step3: Full config for bromine (Z=35)

$1s^22s^22p^63s^23p^64s^23d^{10}4p^5$

Step4: Full config for barium (Z=56)

$1s^22s^22p^63s^23p^64s^23d^{10}4p^65s^24d^{10}5p^66s^2$

Step5: Full config for magnesium (Z=12)

$1s^22s^22p^63s^2$

Step6: Noble gas config for cobalt (Z=27)

$[Ar]4s^23d^7$

Step7: Noble gas config for chlorine (Z=17)

$[Ne]3s^23p^5$

Step8: Noble gas config for tellurium (Z=52)

$[Kr]5s^24d^{10}5p^4$

Step9: Noble gas config for radium (Z=88)

$[Rn]7s^2$

Step10: Noble gas config for rubidium (Z=37)

$[Kr]5s^1$

Step11: Identify element for config 11

Count electrons: $2+2+6+2+4=16$, element is Sulfur

Step12: Identify element for config 12

Count electrons: $2+2+6+2+6+2+10+6+1=37$, element is Rubidium

Step13: Identify element for config 13

Kr has 36, add $2+10+3=15$, total 51, element is Antimony

Step14: Identify element for config 14

Xe has 54, add 2, total 56, element is Barium

Step15: Identify element for config 15

Rn has 86, add 2, total 88, element is Radium

Answer:

1. $1s^22s^22p^63s^1$
2. $1s^22s^22p^63s^23p^64s^23d^6$
3. $1s^22s^22p^63s^23p^64s^23d^{10}4p^5$
4. $1s^22s^22p^63s^23p^64s^23d^{10}4p^65s^24d^{10}5p^66s^2$
5. $1s^22s^22p^63s^2$
6. $[Ar]4s^23d^7$
7. $[Ne]3s^23p^5$
8. $[Kr]5s^24d^{10}5p^4$
9. $[Rn]7s^2$
10. $[Kr]5s^1$
11. Sulfur (S)
12. Rubidium (Rb)
13. Antimony (Sb)
14. Barium (Ba)
15. Radium (Ra)