EQ: • How does the reactivity of metals change across the periodic table?
Identifying the groups • Color the alkali metals blue (use pages 620-…) to fill in your periodic table • Color the alkaline earth metals light green • Color the transition metals yellow • Color the metals in the mixed group purple • Color the actinides dark green • Color the lanthanides orange • Put a yellow circle on the metalloids chemical symbol
Identifying the groups • Outline the boron family in pencil • Outline the carbon family members in red • Outline the nitrogen family members in light blue • Outline the oxygen family members in green • Outline the halogen family members in brown • Outline the noble gases in dark blue • Draw in the stair case in black
Metals, Nonmetals, and Semi-metals Only nonmetal on the metal side Nonmetals are on the right of the stair-step Metals are to the left of the stair- step Semi-metals, “metalloids,” touch the stair-step
Group 1 – The Alkali Metals Most reactive metals on the Periodic Table Alkali metals react with other elements by losing one valence electron. Most common Na (Sodium) and K (Potassium) charge is +1
Group 2 – Alkaline Earth Metals • Still quite reactive. • Each is fairly hard, gray-white, and a good conductor of electricity. • Most common Mg (Magnesium) and Ca (Calcium) • Like to lose 2 valence electrons • Charge is +2 • Video on alkali and alkaline earth metals
T he Groups of the Periodic Table Groups 3-12: Transition Metals Found freely and in compounds in nature Charge is usually +2 Transition metal Video Group 13: Boron Family Charge is +3 (with 3 valence electrons)
Transition Metals • The elements in Groups 3 through 12 are called the transition metals. • The transition metals include most of the familiar metals, such as iron, copper, nickel, silver, and gold. • Most of the transition metals are hard and shiny. • All of the transition metals are good conductors of electricity. • Many of these metals form colorful compounds.
Groups 13-15 • Only some of the elements in Groups 13 through 15 of the periodic table are metals. • These metals are not nearly as reactive as those on the left side of the table. • The most familiar of these metals are aluminum, tin, and lead.
Carbon Family • Each element in the carbon family has atoms that can gain, lose, or share • four electrons (+4 or -4) when reacting with other elements. • In Group 14, only carbon • is a nonmetal. • What makes carbon especially important is its role in the chemistry of life. • Carbon is found in all living things.
Nitrogen Family • Nitrogen is an example of an element that occurs in nature in the form of diatomic molecules, as N2. • A diatomic molecule consists of two atoms. • In this form, nitrogen is not very reactive. -3 charge
Oxygen Family Group 16 • -2 electrons • Like nitrogen, the oxygen you breathe is a diatomic molecule (O2). • Oxygen sometimes forms a triatomic (three-atom) molecule, which is called ozone (O3). • Highly reactive since it can combine with almost every other element. • Most abundant element in Earth’s crust and the second-most abundant element in the atmosphere. (The first is nitrogen.)
Halogen Family • Group 17 contains elements are also known as the halogens, which means “salt forming.” • The most reactive non-metals. • A halogen atom typically has a charge of -1 when it reacts with other elements. Halogen Video
Noble Gases • The elements in Group 18 are known as the noble gases. • They do not ordinarily form compounds because atoms of noble gases do not usually gain, lose, or share electrons. • The noble gases are usually unreactive. Inert Gases
Properties of Metals • Conductivity • Ability to transfer heat or electricity to another object. • Reactivity • The ease and speed that elements combine (or reacts) with other elements and compounds. • Corrosion • Destruction of metal or the gradual wearing away of a metal element due to a chemical reaction.
Special Rows on the PT Lanthanides Actinides
Lanthanides • Two rows of elements are placed below the main part of the periodic table. • The elements in the top row are called the lanthanides (lan thuh nydz). • Lanthanides are soft, malleable, shiny metals with high conductivity. • They are mixed with more common metals to make alloys. An alloy is a mixture of a metal with at least one other element, usually another metal.
Actinides • The elements below the lanthanides are called actinides (ak tuh nydz). • All of the elements after uranium in the periodic table were created artificially in laboratories. (Synthetic) • The nuclei of these elements are very unstable, meaning that they break apart very quickly into smaller nuclei. In fact, many of these elements are so unstable that they last for only a fraction of a second after they are made.
Hydrogen +1 charge • The element with the simplest and smallest atoms. • Each hydrogen atom has one proton and one electron. Some hydrogen atoms also have neutrons. • Because the chemical properties of hydrogen differ very much from those of the other elements, it really cannot be grouped into a family. • Hydrogen is rarely found on Earth as a pure element. Most hydrogen is combined with oxygen in water (H2O).
Metalloids • Along the border between the metals and the nonmetals are seven elements called metalloids. • The metalloids have some characteristics of both metals and nonmetals. • All are solids at room temperature. • They are brittle, hard, and somewhat reactive. • The most common metalloid is silicon (Si). Silicon combines with oxygen to form silicon dioxide (SiO2). Ordinary sand, which is mostly SiO2, is the main component of glass.
Metalloids Continued • The most useful property of the metalloids is their varying ability to conduct electricity. • Whether or not a metalloid conducts electricity can depend on temperature, exposure to light, or the presence of small amounts of impurities. • Metalloids such as silicon, germanium (Ge), and arsenic (As) are used to make semiconductors. • Semiconductors are substances that can conduct electricity under some conditions but not under other conditions. Semiconductors are used to make computer chips, transistors, and lasers.
Summarizer • How does the reactivity of metals change across the periodic table?