Chapter 2 - Matter Section 1 – Classifying Matter Section 2 – Properties of Matter Section 3 – Changes of Matter

Section 1 – Classifying Matter Previously, we watched a 30 minute video on “Properties of matter” Key Questions 1] How can matter be classified? 2] Why are carbon and copper classified as elements? 3] How are elements related to compounds? 4] What is the difference between a pure substance and a mixture?

TN Standards CLE 3202.1.1 – Evaluate pure substances and mixtures

Matter Bellwork A – Which of the following is not an example of matter : ( sunglasses, beach towel, sunlight, water ) Bellwork B – Elements, Compounds, and Mixtures are all ____________ ?

Matter Matter – Anything that has mass and takes up space Matter is either an element, compound, molecule, or mixture Element – a substance that cannot be broken down into simpler substances by chemical means Compounds – substance made of atoms from different elements BONDED TOGETHER

More on Matter Molecule – smallest unit of a substance that behaves like the substance Not always the same as a compound!! Atoms combined but can be same element Compounds are molecules; molecules not always compounds Examples of substances that exist in molecule form, BUT ARE NOT COMPOUNDS: Oxygen and Nitrogen gas in Air Hydrogen and Chlorine gas Phosphorus If a compound: each molecule of that compound will have two or more chemically combined ( BONDED ) elements

More on Matter Compounds have unique properties Table salt, water, sugar, gasoline Molecules have their own chemical formulas H2O, CO2, H2, HF

Atoms What about Atoms – are ( DO ) they matter? Yes! Atoms – smallest unit of an element that maintains the chemical properties of that element Atoms that make up a molecule act as a unit Again, this can be a compound or only a molecule

Pure Substances & Mixtures Pure Substance – matter with definite composition ( or concentration of the components ) Elements, compounds, and molecules Mixtures – combination of substances NOT chemically combined Heterogenous and Homogeneous

Pure Substances and Mixtures What is the difference? Chemical bonds ( mixtures are not chemically bonded ) Example of pure substance? Water, carbon dioxide Example of homogeneous mixture? Salt or sugar water ( dissolved ), vinegar Example of heterogenous mixture? Pulpy orange juice, skittles, salad

Mixtures - Defined Homogeneous – looks the same throughout Heterogenous – does not look the same throughout

Concept Map Word List: Matter, Pure Substances, Atoms?, Elements, Compounds, Mixtures, Homogeneous, Heterogeneous,

Bellwork What are the two different types of mixtures?

Bellwork What are the two different types of mixtures? Homogeneous and Heterogeneous

Section 2/3 – Properties & Changes of Matter Key Questions 1] Why are color, volume, and density classified as physical properties? 2] Why are flammability and reactivity classified as chemical properties? 3] Why is getting a haircut an example of a physical change? 4] Why is baking bread an example of a chemical change? 5] How can mixtures and compounds be broken down?

TN Standards CLE 3202.1.1 – Explore matter in terms of its physical and chemical properties CLE 3202.1.4 – Investigate chemical and physical changes

Physical Properties Physical properties are characteristics observed without changing the identity of the substance Examples: color, texture, density, melting temperature, boiling temperature Physical properties help determine many uses

Chemical Properties Chemical properties are characteristics observed only by changing the identity of the substance Examples: flammability, reactivity

Changes Physical changes do not change the identity of the substance Cutting hair, Cutting paper Can be reversed Chemical changes do Burning, Rusting, Color, Smell Can’t be reversed