Question

$$ \begin{aligned} &\text { 4.116 Complete the following table for atoms or ions: }\\\ &\begin{array}{|l|l|l|l|} \hline \begin{array}{l} \text { Atom } \\ \text { or Ion } \end{array} & \begin{array}{l} \text { Number } \\ \text { of Protons } \end{array} & \begin{array}{l} \text { Number } \\ \text { of Electrons } \end{array} & \begin{array}{l} \text { Electrons } \\ \text { Lost/Gained } \end{array} \\ \hline & 30 p^{+} & & 2 e^{-} \text {lost } \\ \hline & 36 p^{+} & 36 e^{-} & \\ \hline & 16 p^{+} & & 2 e^{-} \text {gained } \\ \hline & & 46 e^{-} & 4 e^{-} \text {lost } \\ \hline \end{array} \end{aligned} $$

Short answer

1. Zn^{2+}: 30 p+, 28 e-, 2 lost2. Kr: 36 p+, 36 e-, no change3. S^{2-}: 16 p+, 18 e-, 2 gained4. Sn^{4+}: 50 p+, 46 e-, 4 lost

Step-by-step solution

Identify the given information

Examine each row in the table to identify the known values for protons, electrons, and electrons lost or gained.

Atom/Ion with 30 protons

For the atom/ion with 30 protons and losing 2 electrons: - 30 protons means it's zinc (Zn). Losing 2 electrons means it has a charge of +2. Thus, Zn^{2+} has 28 electrons.

Atom/Ion with 36 protons

For the atom/ion with 36 protons and 36 electrons: - 36 protons means it's krypton (Kr). No electrons lost or gained, so it's neutral Kr, having 36 protons and 36 electrons.

Atom/Ion with 16 protons

For the atom/ion with 16 protons gaining 2 electrons: - 16 protons mean it's sulfur (S). Gaining 2 electrons means it has a charge of -2. Thus, S^{2-} has 18 electrons.

Atom/Ion with 46 electrons

For the atom/ion with 46 electrons after losing 4 electrons: - 46 electrons + 4 electrons lost = 50 protons. 50 protons mean it's tin (Sn). Losing 4 electrons means it has a charge of +4. Thus, Sn^{4+}.

Complete the table

Fill in the table with the analyzed information:1. Zn^{2+}: 30 protons, 28 electrons, 2 electrons lost2. Kr: 36 protons, 36 electrons, no change3. S^{2-}: 16 protons, 18 electrons, 2 electrons gained4. Sn^{4+}: 50 protons, 46 electrons, 4 electrons lost

Key concepts

Protons in Atoms

Protons are the positively charged particles found in the nucleus of an atom. They play a crucial role because the number of protons determines the element. This number is called the atomic number. For example, an atom with 30 protons is zinc (Zn), while an atom with 36 protons is krypton (Kr). On the periodic table, each element is identified by its unique number of protons. The atomic number can be found directly above the element's symbol.

• Protons define the element
• Protons have a positive charge
• Located in the nucleus

Knowing the number of protons helps us to find out more about an atom, including its electron configuration and properties.

Electrons in Ions

Electrons are negatively charged particles that orbit the nucleus of an atom. In a neutral atom, the number of protons equals the number of electrons. However, ions are formed when atoms either lose or gain electrons, which affects their charge.
For example:

• A zinc ion (Zn²⁺) with 30 protons will have 28 electrons because it lost 2 electrons.
• Krypton (Kr) with 36 protons also has 36 electrons because it did not gain or lose any electrons and is neutral.
• A sulfur ion (S^2-) with 16 protons will have 18 electrons because it gained 2 electrons.
• A tin ion (Sn⁴⁺) with 50 protons will have 46 electrons because it lost 4 electrons.

Understanding how many electrons an ion has allows us to determine its reactivity and electrical conductivity.

Electron Loss and Gain

Atoms form ions by losing or gaining electrons to achieve a more stable electron configuration, often similar to the nearest noble gas.
When an atom loses electrons, it becomes a positively charged ion, known as a cation. For instance, Zn²⁺ means zinc has lost 2 electrons. Tin (Sn⁴⁺) loses 4 electrons to become Sn⁴⁺.
When an atom gains electrons, it becomes a negatively charged ion, known as an anion. For example, S^2- means sulfur has gained 2 electrons.

• Losing electrons = cation (positive charge)
• Gaining electrons = anion (negative charge)

This loss and gain are essential for forming chemical bonds and compounds.

Charge of Ions

The charge of an ion is determined by the difference between the number of protons and electrons. This is essential for understanding how ions interact in chemical reactions.
The charge of an ion is calculated by subtracting the number of electrons from the number of protons.

• If an atom loses electrons, the result is a positive charge. For example, zinc losing 2 electrons results in Zn²⁺.
• If an atom gains electrons, the result is a negative charge. For example, sulfur gaining 2 electrons results in S^2-.

Understanding the charge helps predict how ions will combine to form neutral compounds. For example, forming ionic compounds requires the total positive charge to balance the total negative charge.