Question

(a) What is the range of oxidation states shown by the elements of Group \(5 \mathrm{~A}(15)\) as you move down the group? (b) How does this range illustrate the general rule for the range of oxidation states in groups on the right side of the periodic table?

Short answer

Group 15 elements show oxidation states from -3 to +5. Down the group, the positive states (+3, +5) are more stable and illustrate a trend of higher oxidation states on the right side of the periodic table.

Step-by-step solution

Identify the Elements in Group 15

Group 15 elements include Nitrogen (N), Phosphorus (P), Arsenic (As), Antimony (Sb), and Bismuth (Bi).

Determine the Oxidation States

These elements show a range of oxidation states. Nitrogen can have oxidation states from -3 to +5, as it can gain three electrons or lose five electrons. As we move down the group to Phosphorus, Arsenic, Antimony, and Bismuth, the positive oxidation states (+3 and +5) become more stable, while the negative oxidation states become less common.

Illustrate General Rule for Oxidation States

The elements on the right side of the periodic table typically show a wider range of oxidation states. This pattern is observed in Group 15 as the ability to exhibit both positive and negative oxidation states, with higher positive states becoming more stable down the group. This reflects the general trend where higher atomic number elements in groups on the right side of the periodic table tend to exhibit higher oxidation states and reduced ability to show negative oxidation states.

Key concepts

Oxidation States

Oxidation states, also known as oxidation numbers, represent the degree of oxidation of an atom in a chemical compound. This concept indicates the number of electrons an atom gains, loses, or shares when forming chemical bonds. For instance, in Group 15, elements can exhibit multiple oxidation states like -3, +3, and +5. These numbers explain how many electrons an element donates or accepts during reactions. Nitrogen has a wide range of oxidation states from -3 to +5, illustrating its potential to either gain three electrons or lose up to five. As you go down the group, heavier elements like Bismuth show fewer negative oxidation states and more stable positive oxidation states.

Group 15 Elements

Group 15 of the periodic table includes Nitrogen (N), Phosphorus (P), Arsenic (As), Antimony (Sb), and Bismuth (Bi). These elements are known as the pnictogens. They have five electrons in their outermost shell, leading to various oxidation states.

Some key points about these elements include:

• Nitrogen: Found naturally as N₂, it shows a wide range of oxidation states from -3 to +5.
• Phosphorus: Typically forms +3 and +5 oxidation states, and is found in compounds like phosphates (PO₄³⁻).
• Arsenic: Commonly exhibits +3 and +5 oxidation states, often used in semiconductors and alloys.
• Antimony: Has stable +3 and +5 oxidation states, used in flame retardants and lead-acid batteries.
• Bismuth: Primarily shows +3 oxidation states, with +5 being rare.

As we move down the group, elements tend to show higher positive oxidation states, while negative oxidation states become less stable.

Periodic Table Trends

Elements in the periodic table exhibit patterns and trends that help predict their behavior and reactivity. For Group 15 elements, as you go down the group, some notable trends include:

• Atomic size increases: The radius of the atoms gets larger due to the addition of electron shells.
• Ionization energy decreases: It becomes easier to remove electrons from outer shells.
• Electronegativity decreases: The tendency to attract electrons diminishes.
• Oxidation state stability shifts: Positive oxidation states (+3 and +5) become more stable down the group.

These trends illustrate general rules observed for groups on the right side of the periodic table. As atomic size increases and ionization energy decreases, the elements are likelier to lose electrons and exhibit higher oxidation states. Conversely, negative oxidation states become less common due to the declining electronegativity and increased difficulty in gaining electrons.