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Explore how elements are classified in the Periodic Table, arranged by atomic number, with unique properties and groupings. Learn about metals, nonmetals, metalloids, and noble gases.
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Topic: Chemistry Aim: How are elements classified in the Periodic Table? Do Now: An atom has atomic number of 15. How many protons does it have?
Periodic Table of Elements • System of classifying or all of the known elements and to predict the properties of elements
How are elements arranged? • In order of increasing atomic number
Groups or Families • Columns • Elements have similar BUT NOT identical properties
Hydrogen • Element does not match the properties of any other group so it stands alone • Placed above group 1 not part of group 1 • Very reactive, colorless, ordorless gas at room temp
Ex: Family/Group 1: Alkali Metals • soft, white, shiny metals • highly reactive
2:ALKALINE EARTH METALS Group 2 • White and malleable • Reactive, but less than Alkali metals
3-11:TRANSITION METALS Range of reactivity & wide range of properties Most of the elements on PT
Periods • Rows (7) • Elements not alike in properties • Left to right atomic # increases
4 main categories of elements • Metals, Nonmetals, Metalloids, Noble Gases
1. Metals • 88 elements to left of zigzag line
Physical Properties of Metals • Luster (shininess) • Ductile (can be pulled into wires) • Malleable (can be hammered into sheets) • Good conductors (allow heat and electricity to move through easily)
2. Nonmetals • To right of zigzag line
Physical Properties of Nonmetals • No luster (dull) • Brittle (break) • Poor conductors of heat and electricity
2. Metalloids • Have properties of both metals and nonmetals
Noble Gases • Last group of nonmetals • He, Ne, Ar, Kr, Xe, Rn • INERT gases • Non-reactive
Noble gases glow brightly when electricity is passed through them, and so are used as advertising signs: neon tubes glow red, xenon blue, and krypton bluish-white; argon tubes glow pale red at low pressures, blue at high pressures.
Review: • Explain how the periodic table of elements is arranged. • Elements at the left of the periodic table are known as • Elements at the right of the periodic table are known as • Explain some of the properties of metals. • Explain some of the properties of nonmetals. • Explain some properties of noble gases.
3-11:TRANSITION METALS Good conductors of heat and electricity. Some are used for jewelry. Can bond with many elements in a variety of shapes.
1st element extremely active solid • Last element inactive gas