2.2 The periodic table and chemical properties

Pages 48-53

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By Lester Green Smallwood Academy Gambo

1.16 Describe and explain the role of collecting evidence, finding relationships, and proposing explanations in the development of the periodic table

• See Dmitri Mendeleev page 48• Exercise using elements and periodic table to

identify patterns. Have students list properties of an element on a flash card and place on cupboards doors in classroom.

• Properties: atomic number, atomic mass, name and symbol.

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1.16.1 Identify the periodic table as a listing of all known elements.• All known and yet to be discovered elements are

listed on the Periodic table.• See website www.nclark.net/PeriodicTable

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1.16.2 Describe Mendeleev’s contribution to the development of the modern periodic tableTwo main contributions:1. Elements organized

according to their known physical and chemical properties.

2. Gaps in the tables because he predicted elements were yet to be discovered.

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1.16.3 Distinguish between atomic number and atomic massAtomic Number• It equals the number

of protons in the nucleus of an atom.

• It represents the mass of proton measured in atomic mass units (amu)

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1.16.3 continued…• It equals the number of electrons surrounding the

nucleus. • Atoms are electrically neutral. Therefore, protons

must equal electrons.• Atomic numbers increase by one as it moves from

left to right.

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1.16.3 continued…Atomic Mass• Average mass of atoms

of an element. It is written as a decimal number and measured in amu.

• Mass number is the number of protons and neutrons in an atom of an element.

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1.16.3 continued…• Number of neutrons

can be determined from the mass number and the atomic number.

• Neutrons= mass number – atomic mass

• Atomic mass also increases with some exceptions

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1.16.4 Using atomic mass and atomic number of elements, determine its number of protons, electrons, and neutrons (Hand-out)

WORKSHEETComplete chart showing element name, symbol, atomic number, atomic mass, protons, electrons, and neutrons.

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1.17 Using the periodic table, develop and understanding that the elements are grouped on the basis of similar characteristics

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1.17.1 List properties of metals1. All metals are shiny2. Ductile…ability to

be pulled or stretched Malleable…ability to be bent or moulded into various shapes.

3. Conduct electricity4. Conduct heat

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1.17.2 List properties of non-metal elements1. Dull2. Non-ductile and

non-malleable3. Do not conduct

electricity4. Do not conduct

heat well

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1.18 Using the periodic table, develop an understanding that the elements are grouped on the basis of similar characteristics

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1.19 Use the periodic table to identify new questions and problems that arise from what was learned

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