Classifying Matter: Elements, Compounds, and Mixtures Lesson 12

SPI 0807.9.4 Differentiate between a mixture and a compound. Your Standards SPI 0807.9.3 Classify common substances as elements or compounds based on their symbols or formulas. SPI 0807.9.4 Differentiate between a mixture and a compound.

Key Vocabulary Element Compound Mixture Homogenous Heterogeneous

Include any information about how they are formed. Model Your Learning On a clean piece of paper separate from your notes, illustrate the structure of an element, compound, and mixture. Include any information about how they are formed. Use arrows to represent anything that can not be seen, such as a force.

If atoms are sooo tiny, how can we see them? The only way we can see them with the naked eye is when they are combined into molecules or mixtures. Molecules, however, have different properties than the atoms they are made of. Most of the things around us are made of more than one kind of molecule.

Elements Form Compounds All ordinary substances (not heat, light, or sound) are made up of atoms. Ordinary substances can be classified based on how the atoms are arranged. The three groups of matter are elements, compounds, and mixtures. Elements and compounds are examples of pure substances.

Compounds Elements Pure Substances A sample of matter that has definite chemical and physical properties is a pure substance. It is made up of only one kind of atom or molecule and cannot be separated into its parts by physical means. Compounds Elements

Elements An element is a pure substance that cannot be separated into simpler substance by physical means. Elements are atoms, and atoms are the most basic unit of all matter.

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 Always has more than one capital letter H2O NaCl CO2

Compounds Every sample of a pure substance is made of the same kind of particles, regardless of the source of the sample. A compound is a pure substance that forms when two or more elements join chemically. The atoms of the elements that make up a compound bond to one another. Bonding takes place when atoms join by sharing, giving, or exchanging electrons. The elements can not be separated easily because of this bonding. Chemical means must be used to separate a compound into the elements that form it.

More About Compounds The elements that form a compound do not keep their individual properties. For example, what is salt made of? Sodium and Chlorine. Sodium is a soft metal that explodes when combined with water. Chlorine is a poisonous gas. When they combine, they form the yummy stuff I like on popcorn and fries. Can you separate salt into two parts? Not easily, for sure.

Molecules Molecules are simply the smallest form of a compound that has all the properties of that compound. The makeup of a compound is shown in a chemical formula. A chemical formula used chemical symbols and subscripts to identify the number and types of atoms that make up a compound. For example, water is a compound made up of two elements. What are they? The chemical formula for water is H2O. The 2 in the formula is a subscript, which is a small number written to the right or slightly below a chemical symbol that indicates how many atoms of that element are in the compound. Every compound has a definite composition and its own chemical formula.

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 The substances that form a mixture can be separated far more easily than substances that join to form compounds. A mixture that is unevenly mixed is a heterogeneous mixture. As in, the mixture is uneven. A mixture that is evenly mixed throughout is a homogeneous mixture. As in, the mixture looks like one thing.

Homogeneous mixtures: They are mixtures in which the constituents don't appear separately 1. Blood 2. Sugar solution when sugar is completely dissolved. 3. Mixture of alcohol & water 4. A glass of orange juice 5. salty water (where the salt is completely dissolved) 6. brewed tea or coffee 7. soapy water 8. a dilute solution of hydrochloric acid

Heterogeneous mixtures: Constituents appear separately 1. Oil & water. 2. Soil sample 3.sandy water 4.carbonated beverage (the CO2 gas is mixed with the liquid) 5.orange juice with pulp in it 6. water with ice cubes in it 7.chicken noodle soup 8. sand in a desert

Examples of mixtures: cereal, Chex mix, air. Ocean water is another example. It is made up of mostly two compounds-water and salt. Ocean water can be separated by chemical means. One way is through evaporation.

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. Using a piece of copy paper, make a flag for each of the three. 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

Sum it up- Elements are made of only one atom. Atoms are the most basic unit of all matter. Compounds and mixtures, though, are made up of more than one type of atom. Elements can not be broken down farther than atoms. Compounds can be broken down through chemical reactions. Mixtures can be broken down. Some can be broken down easily. Elements=1 capital letter Compounds=2 or more capital letters Mixtures=no chemical formulas