Chicken noodle soup contains broth, noodles, chicken, and vegetables — several different materials combined together. Each ingredient keeps its own identity and could be separated out. The gold ring, distilled water, and iron block are each made of only one kind of material, making them pure substances.
Question 2 True / False
When you mix salt into water, the salt becomes water.
TTrue
FFalse
Answer: False
False. The salt dissolves and seems to disappear, but it is still salt — it keeps its salty taste and can be recovered by evaporating the water. In a mixture, each substance keeps its own properties even when you cannot see them separately.
Question 3 Short Answer
What is the main difference between a pure substance and a mixture?
Think about your answer, then reveal below.
Model answer: A pure substance is made of only one kind of material, while a mixture is two or more different materials combined together, where each material keeps its own properties.
The key idea is that in a mixture, the ingredients do not lose their identity. Salt water tastes salty because the salt is still salt. You can separate the parts of a mixture using physical methods like filtering or evaporating, which proves the materials were not changed by being mixed.