What is Matter? Matter is… – Anything that has mass and takes up space – You are matter! – Your pencil/ pen is matter!

Atoms Atoms are… – The atom is the smallest unit of an element that maintains the properties of that element.

Atoms The Greek Philosopher Democritus suggested the atomic theory of the universe that stated all things are made up of indivisible and destructible particles called atoms.

Element An element is… – A pure substance made of only one kind of atom. – Examples: C, N, O, Au

Compounds Compounds are… – Substances that are made from atoms of two or more different elements chemically bonded together. – Ex: NaCl, CaCO 3

Molecules Molecules are… – Substances that are made from atoms of two or more alike or different element chemically bonded together. – Ex: O 2, H 2 (diatomics), NaCl

Compounds are ALWAYS molecules! but… Molecules are NOT necessarily Compounds,

Properties of Matter Extensive properties – Depend on the amount of matter present Intensive properties – Do not depend on the amount of matter present

Properties of Matter Extensive - Properties that do depend on the amount of matter present. Mass - A measurement of the amount of matter in a object (grams). Weight - A measurement of the gravitational force of attraction of the earth acting on an object. Volume - A measurement of the amount of space a substance occupies. Length

Properties of Matter Intensive - do not depend on the amount of the matter present. – Color – Odor – Luster - How shiny a substance is. – Malleability - The ability of a substance to be beaten into thin sheets. – Ductility - The ability of a substance to be drawn into thin wires. – Conductivity - The ability of a substance to allow the flow of energy or electricity. – Hardness - How easily a substance can be scratched. – Melting/Freezing Point - The temperature at which the solid and liquid phases of a substance are in equilibrium at atmospheric pressure. – Boiling Point - The temperature at which the vapor pressure of a liquid is equal to the pressure on the liquid (generally atmospheric pressure).

Types of Matter- Solids Solids are… – A matter state having a definite shape and volume. – Atoms are compact and close together with little/no movement – Ex: Nickel, quarter, chair, desk

Types of Matter- Liquids Liquids are… – A matter state having a definite volume but not a definite shape. – Liquids take the shape of the container. – Atoms are compact and close together with some movement – Ex: water, milk

Types of Matter- Gases Gasses are… – A matter state having neither a definite volume nor a definite shape. – Gasses diffuse to fill the room or whatever contains them – Atoms are far apart and there are great numbers of collisions between atoms. – Ex: hydrogen, oxygen

Physical Properties A physical property is… – A characteristic that can be observed or measured without changing the identity of the substance. – Ex: Color, temperature, smell, taste, texture, hardness/ softness

Physical Change A physical change is… – A change in a substance that does not involve a change in the identity of the substance – A physical change can also be a change of state.

Changes of State Change of state (phase change) is… – The physical change from one state to another. – For example: Ice  Water  Vapor and vice versa

Changes of State Define each of the following: - evaporation- sublimation - condensation- boiling point - melting- melting point - freezing- freezing point All of the above are physical transformations.

Chemical Properties Chemical properties refer to… – The ability of a substance to undergo changes that transform into a different substance. – Ex: Flammability, Reactivity

Chemical Changes Chemical change refers to… – The change that occurs when one or more substances transforms into different substances.

Chemical Changes- Reactants vs. Products Reactants are… – The substances that react in a chemical chemical change. The original substance. Products are… – The substances formed by a chemical change that occurs. This is what you get out in the end.

Examples Are the following demonstrations of chemical change or physical change? – Water- Rusty Nail – Paper- Kool-Aid – Wood- Eating Candy – Dry Ice – Sodium- live if possible. Animation: he/english/v html

Reaction of Na + H2O 2 Na + 2 H2O > 2 NaOH + H2 Which is the Reactants? Products? In summary, what happens is the sodium reacts violently with the water producing a lot of heat and hydrogen gas. This hydrogen gas ignites and you see an explosion.

Classifications of Matter- Mixtures Mixtures is… – A blend of two or more kinds of matter each having its own properties and identity. – Do NOT chemically combine! – Ex: Garlic and oil salad dressing, wood, milk

Homogeneous vs. Heterogeneous Homogeneous mixture – A mixture that is uniform in composition. Also, called solutions. – Ex: saltwater, sugarwater Heterogeneous mixture – A mixture not uniform in composition. – Can be separated usually by filter – Ex: blood, wood, fog

Classifications of Matter- Pure Substances A pure substance is… – A substance with a fixed composition and: Every sample of the pure substance has EXACTLY the same properties. Every sample of the pure substance has EXACTLY the same composition.

Pure Substances- Elements and Compounds A pure substance is… – Elements, or… – Compounds/ Molecules Compounds/ Molecules can be broken down into their individual parts. For example, C 6 H 12 O 6 (glucose) can be broken into carbon + water.

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