Question

check all of the following that are mixtures

☐ air

☐ distilled water (h2o)

☐ ocean water (h2o, nacl, kcl, etc)

☐ rhodium (rh)

☐ tree leaves

☐ lead (pb)

☐ methane (ch4)

question 3i

Explanation:

• A mixture is a combination of two or more substances (elements or compounds) that are not chemically bonded in a fixed ratio.
• Air: A mixture of gases (like $\ce{N2}$, $\ce{O2}$, $\ce{CO2}$, etc.).
• Distilled water ($\ce{H2O}$): A pure compound, not a mixture.
• Ocean water: Contains $\ce{H2O}$, $\ce{NaCl}$, $\ce{KCl}$, etc., so it's a mixture.
• Rhodium (Rh): A pure element, not a mixture.
• Tree leaves: Contain various substances (water, cellulose, pigments, etc.), so it's a mixture.
• Lead (Pb): A pure element, not a mixture.
• Methane ($\ce{CH4}$): A pure compound, not a mixture.

Answer:

• Air
• Ocean water (H2O, NaCl, KCl, etc)
• Tree leaves