Question

which of the following pairs of atoms would you expect to combine chemically to form an ionic compound? a. li and s b. o and s c. al and o d. f and cl e. i and k f. h and n

Explanation:

To determine which pairs form an ionic compound, we use the rule that ionic compounds are typically formed between a metal and a non - metal (or a polyatomic ion). Let's analyze each option:

Option a: Li and S

• Lithium (Li) is a metal (alkali metal, Group 1).
• Sulfur (S) is a non - metal (Group 16).
• Metals tend to lose electrons and non - metals tend to gain electrons. Lithium can lose its single valence electron, and sulfur can gain electrons to achieve a stable electron configuration. So, they can form an ionic compound (Li₂S).

Option b: O and S

• Both oxygen (O) and sulfur (S) are non - metals (Group 16).
• Compounds formed between two non - metals are covalent compounds, as they share electrons. So, O and S will form a covalent compound (like SO₂, SO₃ etc.), not an ionic one.

Option c: Al and O

• Aluminum (Al) is a metal (Group 13).
• Oxygen (O) is a non - metal (Group 16).
• Aluminum can lose electrons and oxygen can gain electrons. They form the ionic compound Al₂O₃.

Option d: F and Cl

• Fluorine (F) and chlorine (Cl) are both non - metals (Group 17, halogens).
• They will form a covalent compound (like ClF, ClF₃ etc.) by sharing electrons, not an ionic compound.

Option e: I and K

• Potassium (K) is a metal (alkali metal, Group 1).
• Iodine (I) is a non - metal (Group 17, halogen).
• Potassium can lose its valence electron and iodine can gain it. They form the ionic compound KI.

Option f: H and N

• Hydrogen (H) and nitrogen (N) are non - metals.
• They form covalent compounds (like NH₃) by sharing electrons, not ionic compounds.

So, the pairs that form ionic compounds are:
a. Li and S
c. Al and O
e. I and K

Answer:

To determine which pairs form an ionic compound, we use the rule that ionic compounds are typically formed between a metal and a non - metal (or a polyatomic ion). Let's analyze each option:

Option a: Li and S

• Lithium (Li) is a metal (alkali metal, Group 1).
• Sulfur (S) is a non - metal (Group 16).
• Metals tend to lose electrons and non - metals tend to gain electrons. Lithium can lose its single valence electron, and sulfur can gain electrons to achieve a stable electron configuration. So, they can form an ionic compound (Li₂S).

Option b: O and S

• Both oxygen (O) and sulfur (S) are non - metals (Group 16).
• Compounds formed between two non - metals are covalent compounds, as they share electrons. So, O and S will form a covalent compound (like SO₂, SO₃ etc.), not an ionic one.

Option c: Al and O

• Aluminum (Al) is a metal (Group 13).
• Oxygen (O) is a non - metal (Group 16).
• Aluminum can lose electrons and oxygen can gain electrons. They form the ionic compound Al₂O₃.

Option d: F and Cl

• Fluorine (F) and chlorine (Cl) are both non - metals (Group 17, halogens).
• They will form a covalent compound (like ClF, ClF₃ etc.) by sharing electrons, not an ionic compound.

Option e: I and K

• Potassium (K) is a metal (alkali metal, Group 1).
• Iodine (I) is a non - metal (Group 17, halogen).
• Potassium can lose its valence electron and iodine can gain it. They form the ionic compound KI.

Option f: H and N

• Hydrogen (H) and nitrogen (N) are non - metals.
• They form covalent compounds (like NH₃) by sharing electrons, not ionic compounds.

So, the pairs that form ionic compounds are:
a. Li and S
c. Al and O
e. I and K