Question

classify each of the following samples of matter as an element, compound, solution or mechanical mixture
gasoline
pizza
copper fillings
a cup of coffee
gold
baking soda

Explanation:

To solve this, we recall the definitions:

• Element: Pure substance with one type of atom.
• Compound: Pure substance with two+ bonded elements.
• Solution: Homogeneous mixture (uniform composition).
• Mechanical Mixture: Heterogeneous mixture (non - uniform, visible components).

1. Gasoline

Gasoline is a homogeneous mixture of hydrocarbons. So, it is a Solution.

2. Pizza

Pizza has visible components (dough, cheese, toppings) with non - uniform composition. So, it is a Mechanical Mixture.

3. Copper Fillings

Copper is made of only copper atoms. So, it is an Element.

4. A Cup of Coffee

Coffee (with dissolved solutes like caffeine, flavor compounds in water) is a homogeneous mixture. So, it is a Solution.

5. Gold

Gold consists of only gold atoms. So, it is an Element.

6. Baking Soda (Sodium Bicarbonate, $\ce{NaHCO_3}$)

It is a pure substance made of $\ce{Na}$, $\ce{H}$, $\ce{C}$, and $\ce{O}$ atoms bonded together. So, it is a Compound.

Answer:

• Gasoline: Solution
• Pizza: Mechanical Mixture
• Copper Fillings: Element
• A Cup of Coffee: Solution
• Gold: Element
• Baking Soda: Compound