Don’t worry! It will not be boron. The Periodic Table Don’t worry! It will not be boron.

Activity One Sort your cards! -Card sorting -Dimitri Mendelev -Table Colouring

Periodic Table History Developed the table in 1869 with only 63 known elements Grouped by similar chemical and physical properties hence irregular shape of table Left empty spaces, predicting future elements to be discovered With the empty spaces you could also predict the properties of these elements Periodic Table History

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I make bad chemistry puns… PERIODICALLY

Recall: What is an element?

Elements Currently there are 118 known elements Periodic table organizes all the elements! Each element is noted by an Element Symbol Elements Some periodic tables do not have all 118 elements depending when they are made For Grade 9 Science we will mostly be working with the first 20 elements (you will not have to memorize them) Element Symbol is one or two letter notation that is used on the table Often comes from the Latin words for the elements These are the building blocks of all substances but the amount of them in the world vary For example, only five elements account for over 90% of the Earth's crust: oxygen, silicon, aluminum, iron, and calcium. In contrast, just three elements (oxygen, carbon, and hydrogen) account for over 90% of the mass of the human body.

Element Symbol One or two letters First letter is CAPITALIZED, and second letter is LOWERCASE H - Hydrogen Na - Sodium Cl - Chlorine Element Symbol

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Recall: What is a compound?

H2O Compound Notation Symbol for the element hydrogen Symbol for the element oxygen H2O Compound Notation The small number (subscript) after the element tells us the number of atoms of that element. (There are 2 atoms of hydrogen in this compound) If there is no small number (no subscript) after the element, there is only 1 atom of that element. (There is 1 atom of oxygen in this compound)

Families and Periods Family: The columns of a periodic table Labelled 1-18 Alkali metals, alkaline earth metals, halogens, noble gases Period: The rows of the periodic table Increasing atomic number Same period, similar chemical properties Families and Periods

How metal do you metal? The periodic table can be divided into metals, non-metals and metalloids.

Metals Mostly the left side of the table (before the staircase) Three categories: Alkali metals, Alkaline Earth Metals, Transition Metals (Left to Right) Metals

Properties of Metals Solid Metallic Lustre Malleable, Ductile Only liquid is Mercury (Hg) Metallic Lustre Malleable, Ductile Conducts Electricity Properties of Metals

Metal Families Alkali metals ALKALINE EARTH METALS Group 1 Elements Shiny, Silvery , Soft Highly Reactive Li, Na, K… Metal Families ALKALINE EARTH METALS We do not often encounter these on our own because they are highly reactive Salt instead of just sodium Calcium strong bones and teeth Strontium is used In sea shells Group 2 Elements Not as soft Less reactive, but burn bright colors in flames Be, Mg, Ca…

Mostly the upper right side of the table (before the staircase) Three categories: Noble Gases, Halogens, Other Non- Metals (Right to left) Non- Metals

Properties of Non- Metals Gases or powdery solids Only liquid is Bromine (Br) Brittle Dull Generally poor conductors Properties of Non- Metals -Carbon is an exception to conductors -Take advantage of this to insulate houses in the winter -Insert layer of argon gas to trap heat

Non-Metal Families halogens Noble gases Group 17 Elements F, Cl, Br.. Very reactive Many are poisonous Non-Metal Families Noble gases We do not often encounter these on our own because they are highly reactive Chlorine gas in ww1 or in pools to kill bacteria Iodine is used to clean cuts Helium is used in ballons because low density Often used in bright signs (arong blue, krypton pink, xenon purple, neon red) Except for radon non toxic Group 18 Elements Unreactive He, Ne, Ar…

Metalloids Fall along the “staircase” Except Aluminum Properties of metals and non-metals Metalloids

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Reactivity Once I told a chemistry joke… There was no reaction 

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Alkali Metals

Colouring Sheet