Question

decide which element probably forms a compound with hydrogen that has a chemical formula most and least similar to the chemical formula of the compound formed by hydrogen and oxygen.
comparing chemical formula of compound formed with hydrogen:
\t\t\tchlorine\t\t\t\t\tselenium\t\t\t\t\tpotassium\t\t\t\t\tbromine
most similar to oxygen\t\t○\t\t\t\t\t○\t\t\t\t\t○\t\t\t\t\t○
least similar to oxygen\t\t○\t\t\t\t\t○\t\t\t\t\t○\t\t\t\t\t○

Explanation:

Step1: Recall Oxygen-Hydrogen Compounds

Oxygen forms compounds like \( H_2O \) (water) or \( H_2O_2 \) (hydrogen peroxide). The key is the valence of the element. Oxygen is a non - metal with a common valence of -2 (in \( H_2O \)) or -1 (in \( H_2O_2 \)).

Step2: Analyze Each Element's Valence and Compounds with Hydrogen

• Chlorine (Cl): Chlorine is a non - metal, halogen. It forms \( HCl \) (hydrochloric acid) or \( H_2Cl_2 \) (though more commonly \( HCl \)). But also, like oxygen, it can form compounds with hydrogen where the ratio is related to its valence. Chlorine has a valence of -1 (in \( HCl \)) but can also have other oxidation states. However, bromine is in the same group as chlorine. Wait, let's correct: Oxygen is in group 16, sulfur is also in group 16. Chlorine and bromine are in group 17, potassium is in group 1.
• Sulfur (S): Sulfur is in the same group (group 16) as oxygen. So sulfur forms \( H_2S \) (hydrogen sulfide), which has a similar formula to \( H_2O \) (since both O and S have a common valence of -2 when forming these simple hydrides). So sulfur's compound with hydrogen (\( H_2S \)) has a formula very similar to \( H_2O \).
• Potassium (K): Potassium is a metal (group 1). It forms \( KH \) (potassium hydride), where potassium has a valence of +1 and hydrogen has a valence of -1. The formula is very different from \( H_2O \) as it is a binary hydride of a metal with a 1:1 ratio, while \( H_2O \) is a non - metal hydride with a 2:1 (H:O) ratio.
• Bromine (Br): Bromine is in group 17 (halogen). It forms \( HBr \) (hydrobromic acid), with a 1:1 ratio (H:Br), similar to \( HCl \). But sulfur is in the same group as oxygen, so its hydride formula is more similar.

Step3: Determine Most and Least Similar

• Most Similar to Oxygen: Sulfur (S) forms \( H_2S \), which has the same general formula type (\( H_2X \)) as \( H_2O \) (where X is O or S).
• Least Similar to Oxygen: Potassium (K) forms \( KH \), which has a completely different formula type (1:1 metal - hydride) compared to \( H_2O \) (2:1 non - metal - hydride).

Answer:

• Most similar to oxygen: sulfur (select the radio button for sulfur in the "most similar to oxygen" row)
• Least similar to oxygen: potassium (select the radio button for potassium in the "least similar to oxygen" row)