Question

c. for the following electron configurations determine the possible elements (or ions) they may represent

1. 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁴:
2. 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶:
3. 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹⁰5p⁶6s²4f¹⁰:

20.1s²2s²2p⁶3s²3p⁶4s²3d⁵:

1. kr5s²4d¹⁰5p³:
2. ar4s¹:

23.xe6s²4f¹⁰:

1. ne3s²3p¹:

Explanation:

Step1: Recall electron - configuration rules

The atomic number of an element is equal to the total number of electrons in a neutral atom. For ions, we adjust the number of electrons based on the charge.

Step2: Calculate electrons for 17.

Count the electrons in $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{10}4p^{4}$.
$2 + 2+6 + 2+6 + 2+10 + 4=34$. The element with atomic number 34 is Selenium (Se).

Step3: Calculate electrons for 18.

Count the electrons in $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{10}4p^{6}$.
$2 + 2+6 + 2+6 + 2+10 + 6 = 36$. The element with atomic number 36 is Krypton (Kr).

Step4: Calculate electrons for 19.

Count the electrons in $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{10}4p^{6}5s^{2}4d^{10}5p^{6}6s^{2}4f^{10}$.
$2+2 + 6+2+6+2+10+6+2+10+6+2+10 = 70$. The element with atomic number 70 is Ytterbium (Yb).

Step5: Calculate electrons for 20.

Count the electrons in $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{5}$.
$2+2 + 6+2+6+2+5 = 25$. The element with atomic number 25 is Manganese (Mn).

Step6: Calculate electrons for 21.

[Kr] represents 36 electrons. So for $[Kr]5s^{2}4d^{10}5p^{3}$, we have $36+2 + 10+3=51$. The element with atomic number 51 is Antimony (Sb).

Step7: Calculate electrons for 22.

[Ar] represents 18 electrons. So for $[Ar]4s^{1}$, we have $18 + 1=19$. The element with atomic number 19 is Potassium (K).

Step8: Calculate electrons for 23.

[Xe] represents 54 electrons. So for $[Xe]6s^{2}4f^{10}$, we have $54+2+10 = 66$. The element with atomic number 66 is Dysprosium (Dy).

Step9: Calculate electrons for 24.

[Ne] represents 10 electrons. So for $[Ne]3s^{2}3p^{1}$, we have $10+2 + 1=13$. The element with atomic number 13 is Aluminium (Al).

Answer:

1. Selenium (Se)
2. Krypton (Kr)
3. Ytterbium (Yb)
4. Manganese (Mn)
5. Antimony (Sb)
6. Potassium (K)
7. Dysprosium (Dy)
8. Aluminium (Al)