2. REMEMBER: An element is made of only ONE kind of atom Most atoms found in nature ARE NOT found as elements, but instead found as COMPOUNDS Compound - a substance composed of two or more elements that are chemically combined to form a new substance with new properties. Table salt is a compound
3. Your body is made of many compounds: Water - 60% of your body Proteins - make up skin, bones, tendons, ligaments Membranes - surround cells DNA - determines the traits you inherit
4. What’s the difference between a particle & an element? Each particle of a compound is made of EXACTLY the same ratio of elements. EXAMPLES : Every particle of table salt contains ONE atom of Sodium combined with ONE atom of Chloride. Every particle of water is made with TWO atoms of Hydrogen combined with ONE atom of Oxygen. Properties differ as well. – Sodium Chloride (table salt) has different properties than Sodium & Chlorine. Chlorine - greenish yellow, poisonous gas Sodium - silvery white metal Sodium Chloride - white grains that add flavor to your foods
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6. Let’s look at some more compounds! FeO 3 - Iron Oxide(rust)- 2 elements (1 Iron, 3 Oxygen) Total- 4 atoms CuSO 4 - Copper sulfate- 3 elements (1Copper, 1 Sulfur, 4 Oxygen) Total- 6 atoms H 2 SO 4 - Sulfuric Acid(battery acid)- 3 elements (2Hydrogen, 1 Sulfur, 4 Oxygen) Total 7 atoms CaCO 3 - Limestone(Chalk)- 3 elements (1 Calcium, 1 Carbon, 3 Oxygen) Total- 5 atoms
7. Mixtures Elements & compounds are only 2 ways matter can be classified. Another way is MIXTURES Mixture - combination of substances in which the atoms ARE NOT chemically combined. - can be a combination of elements, compounds or both - retain their properties -can be easily separated using the physical properties it contains
