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Reading the Periodic Table. A way of organizing & classifying elements. Arranged in rows and columns The term “periodic” means repeating in a pattern.
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A way of organizing & classifying elements • Arranged in rows and columns • The term “periodic” means repeating in a pattern. • Once you learn how to read the table it gives you essentially all the information you need to know about the properties of elements and how they will react when combined with other elements. • Its like reading a restaurant menu once you learn how!
Vertical Columns (GROUPS) • The vertical (up and down) columns of the periodic table (there are 18) are called groups or families. • Elements in the same group or family have similar characteristics or properties. • They have the same properties because they have the same number of valence electrons (outer shell electrons)
Valence Electrons • Valence electrons are outer shell/level electrons in an atom. • These are important because they determine how an element reacts chemically with other elements. • Remember that Protons determine identity • Electrons determine reactivityof elements
Horizontal Rows (PERIODS) • The horizontal rows of the periodic table are called periods.----There are 7 periods. • Elements in a period are not alike in properties. • Elements in the same period have the same number of energy levels. • The first element in a period is usually an active solid, and the last element in a period is always an inactive gas.
The number of the period is equal to the number of energy levels for each element
Rows • Atomic radius (due to attraction from increasing number of protons) decreases from left to right across a period. • Atomic mass (number of protons) increases from left to right across a period.
Rows • Metals are on the left • Non-metals are on the right
ALKALI METALS • very reactive metals that do not occur freely in nature • malleable, ductile, good conductors of heat and electricity. • softer than most other metals • can explode if they are exposed to water
ALKLINE EARTH METALS • metals • very reactive • not found free in nature
TRANSITION METALS • ductile and malleable, and conduct electricity and heat • iron, cobalt, and nickel, are the only elements known to produce a magnetic field.
RARE EARTH ELEMENTS • many are man-made
OTHER METALS • are ductile and malleable • are solid, have a relatively high density, and are opaque
METALLOIDS • have properties of both metals and non-metals • some of the metalloids, such as silicon and germanium, are semi-conductors. This means that they can carry an electrical charge under special conditions. This property makes metalloids useful in computers and calculators
NON-METALS • not able to conduct electricity or heat very well • very brittle, and cannot be rolled into wires or pounded into sheets • exist in two of the three states of matter at room temperature: gases (such as oxygen) and solids (such as carbon). • have no metallic luster, and do not reflect light.
HALOGENS • "halogen" means "salt-former" and compounds containing halogens are called "salts" • exist in all three states of matter: • Solid- Iodine, Astatine • Liquid- Bromine • Gas- Fluorine, Chlorine
NOBLE GASES • do not form compounds easily
Let’s Practice…… How many valence e- and energy levels do each of the following elements have? • Sb 2. O 3. Cl 4. Bi 5. Cs 6. Ba 7. Mg 8. Al 9. K 10. Xe