Classifying Matter: Elements, Compounds, and Mixtures
Pre-assessment 1. An element is made up of A. one kind of atom B. two kinds of atoms C. one kind of compound D. two kinds of compounds
2. Heat moves in a predictable flow A. from light objects to heavy objects B. from heavy objects to light objects C. from warmer objects to cooler objects D. from cooler objects to warmer objects
3. Which unit can be used to express the density of a substance. A. g/cm2 B. cm3 C. kg D. kg/m3
4. The mass of an object can be measured using a A. meter stick B. balance C. graduated cylinder D. thermometer
Objectives: By the end of the period you should know: 1. what kind of properties are used to describe matter 2. what are elements and how do they relate to compounds 3. what are the properties of a mixture?
What is matter? Matter is anything that has mass and takes up space.
Properties of matter Chemistry is the study of the properties of matter and how matter changes Some matter are substances = a single kind of matter that is pure. Table salt, sugar, water, baking soda None-pure substances= Flower, milk, eggs, fruit, salt water **Every form of matter has two kinds of properties, physical and chemical.
Physical Properties A physical property is a characteristic of a pure substance that can be observed without changing it into another substance. EX: density, temperature, color, state of matter, conductivity, boiling point, freezing point, melting point, etc.
Chemical Properties A Chemical property is a characteristic of a pure substance that describes its ability to change into another substance. You must try to change a substance into another substance to observe chemical changes EX: flammability, oxidation, reactivity
Atoms Elements Compounds Molecules Pure Substances A sample of matter that has definite chemical and physical properties. Atoms Elements Compounds Molecules
Elements pure substance that cannot be separated into simpler substance by physical or chemical means. The simplest substances
Particles of Elements- Atoms Atom= The basic particle from which all elements are made. Atoms of most elements have the ability to combine. Chemical bonds- when atoms combine because of a force of attraction between them When atoms combine they form molecules= a group of 2 or more atoms held together by chemical bonds.
Compounds Pure substance composed of two or more different elements joined by chemical bonds. Made of elements in a specific ratio that is always the same Has a chemical formula Can only be separated by chemical means, not physically H2O NaCl CO2
Mixtures A combination of two or more pure substances that are not chemically combined. substances held together by physical forces, not chemical No chemical change takes place Each item retains its properties in the mixture They can be separated physically Chem4kids.com
Mixtures There are two types of mixtures, homogeneous and heterogeneous. Homogeneous are the same throughout. A solution is an example of a homogeneous mixture Heterogeneous mixtures have different parts.
Mixtures vs. Compounds http://www.bbc.co.uk/schools/ks3bitesize/science/chemistry/elements_com_mix_6.shtml
Can you identify the following? You will be shown a series of photos. Tell if each photo represents an item composed of an element, compound, or mixture. Review: An element contains just one type of atom. A compound contains two or more different atoms joined together. A mixture contains two or more different substances that are only physically joined together, not chemically. A mixture can contain both elements and compounds.
Element, Compound, or Mixture? Rocks
Element, Compound, or Mixture? Rocks
Element, Compound, or Mixture? Copper
Element, Compound, or Mixture? Copper Cu
Element, Compound, or Mixture? Jelly Beans
Element, Compound, or Mixture? Jelly Beans
Element, Compound, or Mixture? Table Sugar
Element, Compound, or Mixture? Table Sugar C12H22O11
Element, Compound, or Mixture? Diamond
Element, Compound, or Mixture? Diamond C
Element, Compound, or Mixture? Tea
Element, Compound, or Mixture? Tea
Element, Compound, or Mixture? Salt
Element, Compound, or Mixture? NaCl Salt
Element, Compound, or Mixture? Neon Gas
Element, Compound, or Mixture? Ne Neon Gas
Element, Compound, or Mixture? Salad
Element, Compound, or Mixture? Salad
Element, Compound, or Mixture? Pure Water
Element, Compound, or Mixture? Pure Water H2O
Element, Compound, or Mixture? Aluminum
Element, Compound, or Mixture? Aluminum Al
Element, Compound, or Mixture? Lemonade
Element, Compound, or Mixture? Lemonade
Element, Compound, or Mixture? Silver
Element, Compound, or Mixture? Silver Ag
Element, Compound, or Mixture? Sand
Element, Compound, or Mixture? Sand
Notes Detailed notes are located at: http://www.middleschoolscience.com/elements-compounds- mixtures-notes-isn.pdf Flow Chart: http://www.middleschoolscience.com/matter-flow-chart- isn.pdf