2.2 The periodic table and chemical properties Pages 48-53 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.

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

1.16.2 Describe Mendeleev’s contribution to the development of the modern periodic table Two main contributions: Elements organized according to their known physical and chemical properties. Gaps in the tables because he predicted elements were yet to be discovered.

1.16.3 Distinguish between atomic number and atomic mass It equals the number of protons in the nucleus of an atom. It represents the mass of proton measured in atomic mass units (amu)

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.

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.

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

1.16.4 Using atomic mass and atomic number of elements, determine its number of protons, electrons, and neutrons (Hand-out) WORKSHEET Complete chart showing element name, symbol, atomic number, atomic mass, protons, electrons, and neutrons.

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

1.17.1 List properties of metals All metals are shiny Ductile…ability to be pulled or stretched Malleable…ability to be bent or moulded into various shapes. Conduct electricity Conduct heat

1.17.2 List properties of non-metal elements Dull Non-ductile and non-malleable Do not conduct electricity Do not conduct heat well

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

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