Question

which item is a pure substance?
sugar
iced tea
a penny
ocean water

Explanation:

A pure substance has a uniform and definite composition. Sugar (sucrose, \(C_{12}H_{22}O_{11}\)) has a fixed chemical formula and structure. Iced tea is a mixture of water, tea compounds, and often sugar or other additives. A penny (modern US pennies) is a mixture of metals (e.g., zinc and copper). Ocean water is a mixture of water, salts (like NaCl), dissolved gases, etc. So, sugar is the pure substance.

Answer:

sugar