Question

Mark ALL of the PURE SUBSTANCES that are COMPOUNDS below.

A) Bleach, Carbon Dioxide, Baking Soda
B) Iron, Copper, Juice, Table Salt
C) Carbon Dioxide, Baking Soda, Table Salt
D) Oxygen, Juice, Table Salt

Answer 1

Pure substances that are compounds include carbon dioxide, baking soda, and table salt. Elements like iron and copper are pure substances but not compounds, and juice is a heterogeneous mixture. Other substances are classified as either compounds, elements, homogeneous mixtures, or heterogeneous mixtures based on their composition.

Step-by-step explanation:

In chemistry, pure substances can be classified as either elements or compounds. A pure substance that cannot be broken down into simpler substances by chemical changes is an element. Examples include iron, copper, and oxygen. In contrast, a compound is a substance that can be broken down into simpler substances because it contains more than one element; examples are carbon dioxide, table salt, and baking soda.

To answer the student's question regarding which of the listed items are pure substances that are compounds:

1. Option A: Carbon Dioxide, Baking Soda (Bleach is generally a homogeneous mixture)
2. Option B: Table Salt (Iron and Copper are elements; Juice is a heterogeneous mixture)
3. Option C: Carbon Dioxide, Baking Soda, Table Salt (All are compounds)
4. Option D: Table Salt (Oxygen is an element; Juice is a heterogeneous mixture)

Other substances can be classified as follows:

• Salt: Compound (table salt is sodium chloride)
• Pure Water: Compound (water is H2O)
• Soil: Heterogeneous Mixture
• Salt Water: Homogeneous Mixture / Solution
• Pure Air: Homogeneous Mixture / Solution
• Carbon Dioxide: Compound
• Gold: Element
• Bronze: Heterogeneous Mixture (it's an alloy of copper and other metals)