Question

1. fill in the ions

			atom symbol	number of electrons	number of protons	number of valence electrons	number of electrons lost or gained	total number of electrons	protons - total electrons	ion symbol with charge
			be
			o
			k

Explanation:

To solve this, we use the following rules:

• Atomic number (protons) = number of protons in neutral atom.
• In neutral atom, electrons = protons. For ions:
• Cations (lose electrons): electrons = protons - lost electrons.
• Anions (gain electrons): electrons = protons + gained electrons.
• Charge = protons - electrons.

For Be (Beryllium)

Step 1: Protons (Atomic Number)

Be has atomic number 4, so protons = 4.

Step 2: Neutral Electrons

Neutral Be: electrons = protons = 4.

Step 3: Valence Electrons

Be is in Group 2, so valence electrons = 2.

Step 4: Electrons Lost/Gained (Ion)

Be forms \( \text{Be}^{2+} \) (loses 2 electrons). So electrons lost = 2.

Step 5: Total Electrons in Ion

Electrons = protons - lost = \( 4 - 2 = 2 \).

Step 6: Protons - Electrons (Charge)

Charge = \( 4 - 2 = +2 \).

Step 7: Ion Symbol

\( \text{Be}^{2+} \).

For O (Oxygen)

Step 1: Protons (Atomic Number)

O has atomic number 8, so protons = 8.

Step 2: Neutral Electrons

Neutral O: electrons = protons = 8.

Step 3: Valence Electrons

O is in Group 16, so valence electrons = 6 (or 2, but typically 6 for non - metal; gains 2 to fill octet).

Step 4: Electrons Lost/Gained (Ion)

O forms \( \text{O}^{2-} \) (gains 2 electrons). So electrons gained = 2.

Step 5: Total Electrons in Ion

Electrons = protons + gained = \( 8 + 2 = 10 \).

Step 6: Protons - Electrons (Charge)

Charge = \( 8 - 10 = -2 \).

Step 7: Ion Symbol

\( \text{O}^{2-} \).

For K (Potassium)

Step 1: Protons (Atomic Number)

K has atomic number 19, so protons = 19.

Step 2: Neutral Electrons

Neutral K: electrons = protons = 19.

Step 3: Valence Electrons

K is in Group 1, so valence electrons = 1.

Step 4: Electrons Lost/Gained (Ion)

K forms \( \text{K}^+ \) (loses 1 electron). So electrons lost = 1.

Step 5: Total Electrons in Ion

Electrons = protons - lost = \( 19 - 1 = 18 \).

Step 6: Protons - Electrons (Charge)

Charge = \( 19 - 18 = +1 \).

Step 7: Ion Symbol

\( \text{K}^+ \).

Filled Table (Summary)

Atom Symbol	Number of Electrons (Neutral)	Number of Protons	Number of Valence Electrons	Number of Electrons Lost/Gained	Total Electrons (Ion)	Protons - Electrons (Charge)	Ion Symbol with Charge
O	8	8	6	Gained 2	10	-2	\( \text{O}^{2-} \)
K	19	19	1	Lost 1	18	+1	\( \text{K}^+ \)

Answer:

The filled table (key values) is as above. For each ion:

• Be: \( \text{Be}^{2+} \) (protons = 4, electrons in ion = 2, charge = +2)
• O: \( \text{O}^{2-} \) (protons = 8, electrons in ion = 10, charge = -2)
• K: \( \text{K}^+ \) (protons = 19, electrons in ion = 18, charge = +1)