The Periodic Table
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Transcript of The Periodic Table
Arranging Elements
• Demitri Mendeleev – Looked at all the different elements and decided they needed to be put into some sort of order.
• When organizing the elements he began to find similar patterns repeating in the elements. “periodic” means something that repeats,
patterns
• By following the patterns, scientist began to look for elements that filled in holes on the periodic table.
• Eventually, new elements were found to fill in the holes on the periodic table.
Element Squares
Each element is presented on a square, the information within that square provides scientist with a lot of information.
HHydrogen
1.0
1Atomic Number
Chemical Symbol
Element Name Atomic
Mass
Classes of Elements
• Elements have 3 different categories Metals
• Found to the left of the zigzag line, most of them are solids
Non-metals• Found to the right of the zigzag line, more than half
are gases at room temperature
Metalloids• Border the zigzag line, share properties of metals
and non-metals.
Overall Trends
• 3 categories of elements Metals Non metals Metalloids
• Recall that each of these categories of elements share physical and chemical characteristics.
• On your periodic table shade in the following1.Draw the zigzag with red marker2.Metals blue3.Non- metals green4.Metalloids red
States of Elements
• The states of the elements at normal temperature (0 C) and pressure.⁰ Liquids – 80 & 35 Trace those elements in
purple
Gases – 1, 2, 7, 8, 9, 10, 17, 18, 36, 54, 86 Trace the gases in Orange
Organizing Elements
• The periodic table is organized in ways to help chemists understand the various properties of the elements. Can you remember what are examples of the
physical and chemical properties of elements?
Groups
• Group or Family : Vertical column All elements in the same group share
chemical properties On your periodic table label the groups 1 18
• Some of these groups are given names because they share an important characteristic
Special Groups
• Group 1: Alkali Metals
• One valence electron
• Most reactive
• Often stored in oil
• Found in nature in compounds
• Properties: soft, silver colour, shiny
• Group 18 - Nobel Gases
• 8 valence electrons
• Unreactive
• Gases
• Small amounts in atmosphere
• Properties: colourless, odourless,
Groups
• Each column is called a “group”
• Each element in a group has the same number of electrons in their outer orbital, also known as “shells”.
Group 1 = 1 electron
Group 2 = 2 electrons
Except for He, it has 2 electrons
• The electrons in the outer shell are called “valence electrons”
3, 4, 5, 6, 7
Patterns: Groups
• Elements in: Group 1 have 1 valence electron (outer shell)
• 7 missing to be full - VERY REACTIVE
Group 17 have 7 valence electrons• 1 missing to be full - REACTIVE
Group 18 have 8 valence electrons• Full shell - STABLE
Periods
• Periods: horizontal rows on the periodic table Elements in the same period share physical
properties Label Periods 1 7 on your periodic table
Periods
• Each row is called a “period”
1st Period = 1 Shell
2nd Period = 2 Shells
3rd Period = 3 Shells
4th Period = 4 Shells
• The elements in each period have the same number of shells
SO what!?
• Helps identify the chemical and physical properties of elements.
• The periodic table helps scientists predict how elements will react with one another.
• Helps to identify elements that are missing.
Brainpop
• http://www.brainpop.com/science/matterandchemistry/periodictableofelements/
• http://www.nclark.net/Meet_the_Elements.html