Which of the following materials fall in the category of a “pure substance”? Ice, Milk, Iron, Hydrochloric acid, Calcium oxide, Mercury, Brick, Wood, Air.

The break down of our materials and figure out who falls under the category of “pure substances” and who’s in the “mixture” group.

1. Ice:
– Pure substance. Think of it as frozen water; it’s made up of H2O molecules and nothing else.

2. Iron:
– Pure substance. In its elemental form, iron stands alone as a pure substance.

3. Hydrochloric acid:
– Pure substance. It’s like the chemical superhero in our collection, with a specific composition (HCl).

4. Calcium oxide:
– Pure substance. Meet quicklime – it’s a pure substance with a defined composition (CaO).

5. Mercury:
– Pure substance. In its elemental liquid form, mercury is a pure substance.

Now, let’s turn our attention to the more social materials:

– Milk: – Mixture. It’s a blend of water, fats, proteins, lactose, and various other components. No solo act here.

– Brick: – Mixture. A combination of different minerals and materials, not a pure substance.

– Wood: – Mixture. With cellulose, lignin, water, and a variety of components, wood is more of a mix than a pure substance.

– Air:
– Mixture. It’s like a symphony of gases – nitrogen, oxygen, carbon dioxide – definitely not a solo performer.