Important Terms: Element: A pure substance that cannot be broken down into a simpler chemical substance  The building blocks of all substances Ex. silver Compound: a pure substance composed of two or more different elements that are chemically joined Ex. water

Li CN Zn C Au K Kr Ca H2OH2O CO

Introduction to the Periodic Table Metals & Non-metals

History of the Periodic Table Current version evolved from the one developed by Dmitri Mendeleev in 1869 He arranged the elements by increasing mass

If he was organizing the elements according to increasing mass, why isn’t helium right beside hydrogen on the periodic table?

ElementAtomic Mass 1Hydrogen (H) Helium (He) Lithium (Li) Beryllium (Be) Boron (B) Carbon (C) Nitrogen (N)14.01

– Mendeleev noticed there were groups of elements with similar physical and chemical properties – He decided to arrange elements with similar properties under each other, resulting in the irregular shape of the periodic table

Organization of the Periodic Table Periods (rows)  organized by increasing atomic mass Groups / Chemical Family (columns)  organized into groups of elements with similar properties

Chemical Families A column of elements on the periodic table with similar properties

Alkali Metals (Group 1) Lithium (Li), Sodium (Na), Potassium (K), Rubidium (Rb), Cesium (Cs), Francium (Fr) Highly reactive Shiny, silvery and soft Do not often encounter on own because they combine readily with other elements and compounds Potassium is found in many plant foods such as oranges and bananas and is important to the function of all living cells

Alkaline Earth Metals (Group 2) Beryllium (Be), Magnesium (Mg), Calcium (Ca), Strontium (Sr), Barium (Ba), Radium (Ra) Shiny and silvery but not as soft or reactive as the alkali metals Calcium helps build strong bones and teeth Many substances composed of alkaline earth metals burn with bright, colourful flames, which is why magnesium is often used in fireworks

Halogens (Group17) Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I), Astatine (At) At room temperature, fluorine and chlorine are gases, bromine is a liquid and iodine and astatine are solids Highly reactive, therefore rarely found in elemental form in nature Often form compounds with alkali metals Poisonous in large amounts and chlorine can be poisonous in even small amounts Chlorine is used in small concentrations to kill bacteria in swimming pools Iodine dissolved in alcohol can be used to disinfect cuts Bromine can be added to light bulbs to increase the brightness and life of bulb

Noble Gases (Group 18) Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), Radon (Rn) Very stable The low density of helium makes it ideal for use in balloons Although noble gases are colourless, odourless and tasteless, they glow brightly when an electrical current is passed through them and are what produces the light in neon signs Argon glows blue, krypton glows pink, xenon glows purple and neon glows red With the exception of radon (due to its radioactivity), the noble gases are non-toxic

METALS AND NON-METALS

Metals An element that is lustrous, malleable, ductile and conducts heat and electricity A lot of metals have a shiny lustre that we identify as metallic – Examples: copper, silver, gold, nickel, tin Some metals, however, have a coating, and you might not think they’re metallic on first glance -Examples: lithium, sodium, potassium Easy to shape

COPPER (Cu)SODIUM (Na) Soft, pinkish orange metalSoft, silvery white metal Sodium and copper are both metals. Why is it that sodium cannot be used in chemical wires and copper can be?

Many uses for metals copper and aluminum for pots and pans  easy to shape and good conductors of thermal energy copper for electrical circuits  very malleable and ductile and a good conductor of electricity gold and silver for jewellery  lustre, malleability and resistance to corrosion

Non-Metals Easily distinguishable from metals because most are either gases or dull powders at room temperature They are not shiny, ductile or malleable Bromine is the only liquid non-metal Non-metals are generally poor conductors of thermal energy and electricity We take advantage of this property to insulate our houses in the winter

ARGON (Ar) a gas that glows blue when an electrical current is passed through it low thermal conductivity Why is a layer of argon sometimes inserted between the two panes in double-glazed windows in homes?

METALSNON-METALS can be flattened and easily shaped is soft and shiny symbol located in the first column of the periodic table used in electrical circuits is a gas under normal conditions it’s symbol is located in the upper right corner of the periodic table is a dull powder shatters when struck

Metalloids An element that has properties of both metals and non-metals – Boron – Silicon – Germanium – Arsenic – Antimony – Tellurium – Polonium

Boron (B)Silicon (Si) Germanium (Ge) Antimony (Sb)Tellurium (Te) Arsenic (As)

Colour Coding and Labelling the Periodic Table Metals are located on the left and central parts of the periodic table Non-metals are located on the upper right portion of the periodic table Metalloids are located along the ‘staircase’ line

Label: – groups – periods – alkali metals – alkali earth metals – halogens – noble gases Colour Code: – metals – metalloids – non-metals

Agree / Disagree? Water is a common element. It is easy to change one element into another. Elements are arranged alphabetically on the periodic table. FALSE