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Chemistry. Chemical Families. What are Chemical Families?. A group (column) of elements with similar properties of the periodic table. In Grade 9, we will look at four families. Alkali Metals (Group 1).
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Chemistry Chemical Families
What are Chemical Families? • A group (column) of elements with similar properties of the periodic table. • In Grade 9, we will look at four families.
Alkali Metals (Group 1) • Elements Present: Lithium (Li), Sodium (Na), Potassium (K), Rubidium (Rb), Cesium (Cs), Francium (Fr) • Physical Properties: Shiny, silvery, soft, low density, solid • Chemical Properties: highly reactive, most reactive metals
Alkaline Earth Metals (Group 2) • Elements Present: Beryllium (Be), Magnesium (Mg), Calcium (Ca), Strontium (Sr), Barium (Ba), Radium (Ra) • Physical Properties: Shiny, silvery, harder than group #1, more dense than group #1, solid. • Chemical Properties: fairly reactive, burn with colourful flames.
Halogens (Group 17) • Elements Present: Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I), Astantine (At) • Physical Properties: Varying states at room temperatures. • Chemical Properties: Highly reactive, most reactive non-metals. • Fluorine most reactive >> Astantine least reactive • Opposite to metals.
Noble Gases (Group 18) • Elements Present: Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), Radon (Rn) • Physical Properties: Gases at room temperature, colourless, odourless, tasteless. • Chemical Properties: Unreactive (very stable), glow bright colours when current is passed through them. • Also known as: Inert Gases
Metals • Shiny • Good conductor of heat and electricity • High melting point • Malleable • Usually solid at room temperature (Hg is only exception)
Non-Metals • Not shiny • Usually bad conductors of heat and electricity • May be solids, liquids or gas at room temperature
Metalloids • Have properties in between or a mixture of metals and non-metals • Metallic appearance • Brittle • Fair conductors of electricity • Zigzag line on periodic table • Boron, silicon, germanium, arsenic, antimony, tellurium • Less recognized: carbon, aluminum, selenium, polonium, astatine