Question

complete the steps in the formation of a potassium ion.

1. an atom of potassium has electron

in its energy level.

1. a potassium atom one electron in

its outer energy level when it combines with an iodine
atom.

1. the potassium atom is now an
2. the potassium ion has a charge of
3. the symbol for a potassium ion is

analyze why are group 14 elements much more likely to share
electrons than transfer electrons?
get it? explain what part of an ions symbol indicates its charge?
get it? explain why an atom of iodine tends to react to gain one
electron

Explanation:

Step - by - Step Format:

Step 1: Electron configuration of potassium

Potassium (\(K\)) has an atomic number of \(19\). Its electron configuration is \(1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{1}\). So, an atom of potassium has \(1\) electron in its outer (valence) energy level.

Step 2: Electron transfer

When a potassium atom combines with an iodine atom (which needs one electron to complete its octet), the potassium atom loses one electron in its outer energy level.

Step 3: Ion formation

Since the potassium atom has lost an electron (a negatively - charged particle), the number of protons (\(19\)) is greater than the number of electrons (\(18\)). So, the potassium atom is now an ion.

Step 4: Charge calculation

The charge of an ion is calculated as \(n_{p}-n_{e}\), where \(n_{p}\) is the number of protons and \(n_{e}\) is the number of electrons. For potassium ion, \(n_{p} = 19\) and \(n_{e}=18\). So, the charge is \(+ 1\) (because \(19 - 18=+1\)).

Step 5: Ion symbol

The symbol for a potassium ion is \(K^{+}\)

Analyze:

Group 14 elements have \(4\) valence electrons. If they were to transfer electrons:

• To gain a full outer shell by gaining electrons, they would need to gain \(4\) electrons. But gaining \(4\) electrons would result in a highly negative charge (\(-4\)), which is energetically unfavorable.
• To lose electrons, they would need to lose \(4\) electrons, resulting in a \(+4\) charge, which is also energetically unfavorable.
• Sharing electrons (covalent bonding) allows them to achieve a more stable electron configuration without forming highly charged ions.

Get It? (First question)

In an ion's symbol, the superscript indicates its charge. For example, in \(K^{+}\), the “\(+\)” in the superscript indicates the charge.

Get It? (Second question)

Iodine has an atomic number of \(53\). Its electron configuration is \(1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{10}4s^{2}4p^{6}4d^{10}5s^{2}5p^{5}\). It has \(7\) valence electrons. To achieve a stable octet (a full outer shell of \(8\) electrons), it needs to gain \(1\) electron.

Answer:

1. \(1\)
2. loses
3. ion
4. \(+1\)
5. \(K^{+}\)

Analyze: Group 14 elements have 4 valence electrons. Gaining or losing 4 electrons is energetically unfavorable, so sharing is preferred.
Get It? (First question): The superscript.
Get It? (Second question): Iodine has 7 valence electrons and needs to gain 1 to achieve a stable octet.