🧪 Grade 9 Chemistry: Key Concepts & Fun Facts! Chemistry is the science of matter – what it's made of, how it changes, and how it reacts. It’s like the recipe book of the universe, and in Grade 9, you’ll start learning the basics that explain the world around you. Here's a quick guide to get you started: 🔹 1. Matter and Its States Matter is anything that has mass and takes up space. It exists in 3 main states : Solid, Liquid, and Gas. (Plasma is the 4th state, but it’s more advanced.) Physical changes (like melting or freezing) don’t change what the substance is, but chemical changes do (like rusting or burning). Fun Fact : Ice, water, and steam are all the same substance – just in different states! 🔹 2. Elements, Compounds & Mixtures Element : A pure substance made of only one type of atom (e.g., Oxygen – O). Compound : Two or more elements chemically combined (e.g., Water – H₂O). Mixture : Two or more substances physically combined (e....