1 Unit 2: Chemistry Lesson 2: Classifying Matter Essential Questions: 1 Unit 2: Chemistry Lesson 2: Classifying Matter Essential Questions: 1.) What is matter made of? 2.) What are two types of mixtures?
2 What is matter made of?A substance that cannot be broken Elementdown into any other substances bychemical or physical meansElements are the simplest substancesThey are identified by physical and chemical propertiesThey are represented by one or two letter symbols
3 Each element has:physical and chemical propertiesone or two letter symbols
4 The basic particle from which Atom all elements are madeAll matter is made of atomsIt has a positively charged center, or nucleus, surrounded by a “cloud” of negative chargeElements have different properties becausetheir atoms are different
5 Atom Positively charged nucleus and smaller particles Cloud of negative charge
6 A force of attraction between Chemical bond two atomsA group of two or more atoms Moleculesheld together by chemical bondsThe atoms can be atoms of the same elementor different elements
7 Water is a molecule made up of an oxygen atom chemically bonded to two hydrogen atoms. Oxygen molecules are made up of two oxygen atoms chemically bonded.Chemical bond
9 A substance made of two or more Compound elements that are chemically combined in a set ratioThis formula shows the elements Chemical Formula in the compound and the ratio ofatomsThe chemical formula for water is H2O. There are two hydrogen atoms and 1 oxygen atom in water.
10 When elements combine, they form compounds with properties different from those of the elements. Chemistry Textbook page 11
11 What are the two types of mixtures? Two or more substances that are Mixturetogether in the same place,but their atoms are not chemically bondedEach substance in a mixture keeps its own propertiesThe parts can be separatedA salad is a mixture. It includes lettuce, carrots, tomatoes, onions and croutons. You can separate the items.
12 In this mixture, you can usually see Heterogeneous the different parts and theycan be separatedIn this mixture, the substances Homogeneousare so evenly mixed that youcan’t see the different parts
13 MixturesWhich of these foods are heterogeneous and which are homogeneous?