Chemistry Notes Ms. Feffer, Mr. Sharp, and Mrs. Wingate

Matter Anything that has a mass and a volume Matter

Physical Properties Chemical Properties Are used to classify elements are boiling point, melting point, color, hardness, and density. Used to separate elements from each other including flammability, reactivity with acids, or reactivity with oxygen. Physical & Chemical

Physical Change Chemical Change Changing from one state to another is a physical change. If a new substance is formed it is a chemical change. Physical vs. Chemical Change Images are from

Atom The building block of Matter Consist of Protons (+), Electrons (-), and Neutrons (N). Very Small Images are from

Molecule o Consist of 2 or more atoms of the same element, or different elements, that are chemically bound together. o In the animation below, two nitrogen atoms (N + N = N2) make one Nitrogen molecule. Molecule

Pure Substance o A substance made up of only ONE type of particle o Elements are pure substances. Example: Every particle in a 5g gold nugget is like every other particle of gold, no matter where they are found Pure Substance

Elements o Consist of only one kind of atom. o Cannot be broken down into smaller type of matter by either physical or chemical means. o Can exist as either atoms or molecules Element

Composition Pie Chart By percent, the Earth breaks down as follows: Oxygen-O2 46.6% Silicon-Si 27.7% Aluminum-Al 8.1% Iron-Fe 5.0% Calcium-Ca 3.6% Sodium-Na 2.8% Potassium-K 2.6% Magnesium-Mg 2.1% others 1.6%

Abundance of elements in the Earth The following pie chart shows the percentage by mass of elements in the Earth's crust.

Properties of Compounds Compounds, like elements, can be identified by their own physical and chemical properties. Atoms of 2 or more different elements bound together Can be separated into elements chemically, but not physically. Compounds In the animation above, water (H 2 0) is a compound made of Hydrogen and Oxygen. Animated images and notes from

Question: How is an element different from a compound? Answer: Element = Examples: Gold (Au), Silver(Ag), Oxygen (O), Iron (Fe) Compound = Example- Flouride ( ), Water (H 2 O), Carbon Dioxide (CO 2 )  Answer:  A pure substance that canNOT be separated into simpler substances by physical or chemical means  is composed of two or more elements that are chemically combined. Element vs. Compound

Elements have: o Unique properties that do not depend on the amount of the element present Elements

Elements are identified by 3 main categories o Metals o Nonmetals o Metalloids Elements Are Grouped by:

The Three Groups of Elements MetalsNonmetalsMetalloids ShinyDullSome shiny, some dull Malleable and ductile Brittle and unmalleable Somewhat malleable and ductile Good conductors of electricity and heat Poor conductors Semi- conductors

Metals o They are all grouped together on the left hand side of the Periodic Table. o Not all metals are exactly alike, but they do have some properties in common. o **Metals are elements that are usually shiny and good conductors of electricity and heat. Elements Are Grouped by:

Metals o Metals are also malleable (can be hammered into thin sheets). o Chemical property of metal is its reaction with water which results in corrosion. o Metals are ductile, or can be drawn into thin wires. o Examples: Iron (Fe) and Copper (Cu). Elements Are Grouped by:

Nonmetals o Usually dull and poor conductors of heat and electric current. o Tend to be brittle and unmalleable. o Many non-metals are gases o Nonmetals are located to the right of the “zig zag line” on the Periodic Table. o Examples: Neon (Ne) and Carbon (C) Elements Are Grouped by:

Metalloids ●Share properties of both metals and nonmetals. ●They conduct heat and electricity better than non-metals but not as well as metals. ●Can be shiny or dull. ●Somewhat malleable and ductile. ●Examples: Silicon (Si) Arsenic (As). Elements Are Grouped by:

Metals are located to the left, non metals to the right and metalloids touch both side of the “zig zag” line on the periodic table. Non- Metals Metals Metalloids

Looking at the Periodic Table Notice that the Largest portion of Elements in our Earth come from the first 20 elements in the Periodic Table

Dmitri Mendeleev In 1869, Dmitri Ivanovitch Mendeléev created the first accepted version of the periodic table. He grouped elements according to their atomic mass, and as he did, he found that the families had similar chemical properties. Blank spaces were left open to add the new elements he predicted would occur. Creator of Periodic Table

Properties of Compounds o Compounds, like elements, can be identified by their own physical and chemical properties. o The compound Water is composed of Hydrogen and Oxygen chemically bonded together. *Remember*

Properties of Compounds Can be broken down into simpler substances (elements or simpler compounds) Only through chemical changes Examples:  Water can be broken down into hydrogen and oxygen through electrolysis  Carbonic acid breaks down into carbon dioxide and water when you open a soda *Remember*

Compounds you need to know! Compounds - The way a compound is written is called it’s FORMULA Familiar Compound Compound Elements Combined Table Salt (NaCl) Sodium and Chlorine (Na + Cl) Water (H 2 O) Hydrogen and Oxygen (H + H + O) Hydrocloric Acid (HCl) Hydrogen and Chlorine (H + Cl) Carbon Dioxide (CO 2 ) Carbon and Oxygen (C + O + O) Methane (CH 4 ) Carbon and Hydrogen (C + H + H + H + H) Baking Soda (NaHCO 3 ) Sodium, Hydrogen, Carbon, and Oxygen (Na + H + C + O + O + O)

Comes from… o Sodium – soft, silvery white metal that reacts violently with water o Chlorine – poisonous, greenish yellow gas Sodium Chloride (table salt)

Precipitate Is when a solid that is formed when two liquids are mixed together and the solid does not dissolve. May be one of the most common signs of a chemical reaction taking place. Precipitates should not be confused with suspensions, which are solutions that are homogeneous fluids with particles floating about in them. Example: when a soluble carbonate reacts with Barium, a Barium Carbonate precipitate can be observed. Formation of a Precipitate

Which is an element? Which is a compound? ___ H ___O ___NaCl ___H2O ___HCl ___He Let’s Practice