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Periodic Trends.

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Presentation on theme: "Periodic Trends."— Presentation transcript:

1 Periodic Trends

2 Arrangement Elements are arranged according to atomic number
Number of protons Not atomic mass

3 Group/Family Vertical column in the periodic table 18 groups
Elements in same group Same physical and chemical properties Same number of electrons in last energy level Example: Group 18 All gases All unreactive

4 Valence electrons Electrons in the last energy level of an atom
Involved in chemical reactions and bonding Coincides with the unit’s place on the group number except for Groups Group 1: 1 valence electron Group 2: 2 v.e. Group 18: 8 v.e. except for He

5 Lewis Dot Diagram Shows the number of valence electrons in a neutral atom Each dot represents 1 valence electron

6 Lewis Structure Practice
Carbon Hydrogen Calcium Oxygen

7

8 Metals Left and middle of periodic table except H Properties:
Ductile: drawn into a wire Malleable: hammered into thin sheets Good conductors of heat/electricity Luster: shine Solid at room temperature (except for Hg)

9 Nonmetals Far right side of periodic table Properties
Brittle: break when hammered Lack luster Poor conductors Solid or gas at room temperature (except Br)

10 Metalloids (Semi-metals)
Along the black line that divides metals and nonmetals Have properties of both metals and nonmetals

11 3 states of matter Liquid: Gas: Solid: Hg and Br
all the noble gases (group 18) and O, F, N, H, Cl Solid: rest of the elements in the periodic table

12

13 Ions Charged elements Metals Nonmetals
Positive ions (lose electrons) to have a complete valence shell Magnesium  Mg2+ Nonmetals Negative ions (gain electrons) to fill valence shell Nitrogen  N3-

14 Relationship between charge and group

15 State the charge of the following elements as ions
Fluorine Phosphorus Beryllium Aluminum


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