Matter and the Periodic Table Unit 4 Matter and the Periodic Table

Physical Properties Any physical attribute of a substance Color Density Hardness Melting/Boiling points Solubility Luster/texture

Physical Changes Physical properties can change without changing the identity of the substance Melting ice, ripping paper These are called physical changes – when a substance changes its phase or any physical property but NOT its identity

Chemical Properties Describe the ability of a substance to change its chemical identity Baking soda bubbles when mixed with vinegar Copper reacts with water and carbon dioxide to form a green substance called patina Wood will burn and change to ash

Chemical Changes A change in a substance that involves the rearrangement of the atoms to make a new substance AKA chemical reactions

Chemical or Physical? What two changes happen when a candle burns? HW: Worksheet Physical Changes No change in the identity of the substance Can usually be reversed Chemical Changes Make an entirely new substance Can not be reversed without another chemical reaction What two changes happen when a candle burns? Wax melting – physical change Wick burning – chemical change

Elements, Compounds, and Mixtures With all of the different substances on the Earth, it might seem like there are millions of types of atoms Really, there are only a little more than one hundred It is the COMBINATION of these atoms that make so many different substances Element A material that consists of only one type of atom Can be found on the periodic table

Identification of Elements On the periodic table, elements are listed by their atomic symbol All symbols contain one capital letter Some also contain a lowercase letter Usually match up easily to the element name Carbon = C; Chlorine = Cl; Cadmium = Cd

Elements with Latin Names Some symbols do not match up with their element names because the symbols are taken from the original Latin names of the elements Gold (Au) – Aurum Lead (Pb) – Plumbum Sodium (Na) – Natrium Potassium (K) – Kalium Iron (Fe) – Ferrum Copper (Cu) – Cuprum Silver (Ag) – Argentum Tin (Sn) – Stannum Mercury (Hg) – Hydrargyrum Antimony (Sb) – Stibium Tungsten (W) - Wolfram

Elemental Formulas How do we know if atoms travel individually or in groups? Elemental Formulas – Tell how many atoms travel together in the elemental form Use the symbols for the element and a subscript directly after the element to show how many Gold atoms travel individually, so its elemental formula is just Au Nitrogen atoms travel in pairs, so its elemental formula is N2

Compounds Atoms of different elements bonded together to make a totally new substance with its own properties Represented by a chemical formula, in which the symbols for the involved atoms are written together: Table salt is NaCl, one sodium atom and one chlorine atom Water is H2O, two hydrogen atoms and one oxygen atom Ammonia is NH3, one nitrogen atom and three hydrogen atoms

Compounds Compounds have totally different chemical and physical properties than the elements that are contained in them Water contains hydrogen and oxygen, which are both gases Table salt contains sodium (a metal) and chlorine (a poisionous gas) Forming a compound is a chemical change because the substances change their identities and form new properties

Mixtures A combination of two or more substances in which each substance retains its original properties Forming a mixture is a physical change because the substances don’t change their properties, they are just mixed together Mixtures can be physically separated A solid mixed with a liquid can be filtered out of the mixture Two liquids mixed together can be separated using distillation

Classification of Matter Pure Impure / Mixture Elements Compounds Heterogeneous Mixture Homogeneous Mixture Mixture in which particles can be visually separated Mixture that looks the same throughout Solution Suspension All components are in a single phase Components are in different phases

Modern Periodic Table C Arranged in order of increasing atomic number Vertical Columns – Groups/Families Have similar properties Horizontal Rows – Periods Include the same outer principal energy level Each block contains information on a single element: 6 C Carbon 12.011 Atomic Number Atomic Symbol Name Average Atomic Mass

Metals, Non-Metals, and Metalloids Are good conductors of heat and electricity Malleable – able to be hammered into shapes Ductile – able to be drawn into wires Non-Metals Are poor or non-conductors of heat and electricity Are brittle/easily broken Metalloids Have properties of both metals and non-metals

Separates the metals from the non-metals Metalloids

Groups/Families Each column (group) shares traits with other group members Many groups have special names

Alkali Metals (Group 1) Very reactive with water and with group 17 Reactions get more intense as you go down the group Video: Reactions with Water

Alkaline Earth Metals (Group 2) Frequently form oxides that are basic (alkaline) in solution with water Oxides melt at such high temps that they remain solid in fire Soft, silver colored metals:

Transition Metals (Groups 3-12) Traditional Metals Used in currency, wires, etc Malleable – able to be hammered into shapes Ductile – Able to be drawn into wires

Boron Group (Group 13) Boron is a metalloid, all of the rest are metals Mainly similar in the ways that they bond

Carbon Group (Group 14) Most are relatively common elements in everyday life Not necessarily elements found in great abundance

Nitrogen Group (Group 15) Also called the pnictogens Form very stable compounds using double and triple bonds Tend to form potentially toxic compounds

Oxygen Group (Group 16) Also called the chalcogens Very common in minerals

Halogens (Group 17) Very reactive, usually only found as ions or in compounds Diatomic in their elemental states Only group to represent all three matter phases at room temperature

Noble Gases (Group 18) Generally have no reactions with other elements Melting points and boiling points are very close together, so they are only liquids over a small range

Inner Transition Metals PT Activity Most are radioactive, and many are lab created 2 series: Lanthanide Series Actinide Series