Classify each substance as an element, a compound, a homogeneous mixture or a heterogeneous mixture.
i. nitrous oxide
ii. rainwater
iii. silver
iv. salad

• A. i: heterogenous mixture; ii: homogenous mixture; iii: compound; iv: element
• B. i: compound; ii: homogenous mixture; iii: element; iv: heterogenous mixture
• C. i: homogenous mixture; ii: compound; iii: element; iv: homogenous mixture
• D. i: element; ii: homogenous mixture; iii: heterogenous mixture; iv: compound

Answer: (B)