Elements and Their Properties Chapter 20 Elements and Their Properties

Chapter 20 Section 1: Metals

You will learn how to…….. Describe the properties of a typical metal Identify the alkali metals and alkaline earth metals Differentiate among three groups of transition elements This is important because metals are a part of your everyday life--- from electric cords to the cars you ride in.

Metals on the Periodic Table On the periodic table, the metals are found on the LEFT side of the zig-zag line.

Properties of Metals Conduct heat and electricity Luster (shiny) Malleable (bendable or able to shape) Ductile (Drawn into wires) Solid at room temperature (EXCEPT Mercury (Hg)= liquid)

Metals Valence electron Metals generally have 1-3 electrons on their outer energy level (valence electrons). In chemical reactions, metals tend to GIVE UP electrons easily because they are close to having an empty outer energy level. 3 P 4N Lithium

Metals When a metal GIVES UP an electron, the atom then has MORE protons than electrons and the atom is no longer neutral. The atom is MORE POSITIVE. When a metal gives up an electron it becomes a positively charged ion. Na gave up an electron to Cl. The Na atom becomes a positively charged ion because it has more protons than electrons.

Bonding in Metals When metals give electrons to nonmetals, an ionic bond is formed. Metal (Na) + Nonmetal (Cl) = Ionic Bond (NaCl)

Types of Metals Alkali Metals Alkaline Earth Metals Transition Elements Inner Transition Elements

Alkali Metals Located in GROUP 1 of the periodic table MOST HIGHLY REACTIVE because they only have 1 valence electron, so these elements are NOT found free in nature Gives away the 1 valence electron because it is easier to LOSE 1 versus gaining 7 electrons to complete the octet (8 electrons) +1 ion

Alkali Metals Some uses of Alkali Metals Living things need potassium and sodium compounds to stay healthy. Doctors use lithium compounds to treat bipolar depression

Alkaline Earth Metals Located in GROUP 2 of the periodic table 2nd MOST HIGHLY REACTIVE because they only have 2 valence electron, so these elements are NOT found free in nature Gives away the 2 valence electrons because it is easier to LOSE 2 versus gaining 6 electrons to complete the octet (8electrons) +2 ion

Alkaline Earth Metals Some uses of Alkaline Earth Metals Magnesium and strontium are used in are used in fireworks to produce the brilliant white color and the bright red flashes. Calcium compounds are needed for life. Calcium compounds in your bones helps make them strong.

Transition Metals Located in GROUP 3-12 of the periodic table Iron Triad = iron, cobalt, nickel (used to make steel and other metal mixtures) Coinage metals = copper, silver, gold (used to make coins)

Inner Transition Metals Located at the bottom of the periodic table Lanthanides Actinides- ALL are unstable and radioactive- nucleus breaks down and gives off particles and energy

Chapter 20 Section 2: Nonmetals

You will learn how to…….. Recognize hydrogen as a nonmetal Compare and contrast properties of the halogens Describe properties and uses of the noble gases This is important because nonmetals are not only all around you, the are an essential part of your body!

Nonmetals on the Periodic Table On the periodic table, the nonmetals are found on the RIGHT side of the zig-zag line. REMEMBER: HYDROGEN IS A NONMETAL!

Properties of Nonmetals Poor conductors of heat and electricity No luster (not shiny) Not malleable (bendable) Not ductile (CAN NOT be drawn into wires) Usually gases OR brittle solids (EXCEPTION: Bromine (Br) = liquid) Sulfur Oxygen

Did you know….. Most of your body mass is made up of nonmetals! oxygen, carbon, hydrogen, and nitrogen

NONMETAL + NOMETAL = COVALENT BONDING Bonding in Nonmetals Nonmetals tend to GAIN electrons to become stable. When a nonmetal gains an electron it becomes a NEGATIVELY charged ION. NONMETAL + NOMETAL = COVALENT BONDING (SHARE electrons)

Hydrogen Highly reactive Is a nonmetal that acts like a metal

Diatomic Molecules Diatomic molecule – consists of two atoms of the same element in a covalent bond. Hi Bronclf ( HI BrONClF) H2, I2, Br2, O2, N2, Cl2, F2) H SHARE electrons

Nonmetals Halogens Noble Gases

The Halogens Located in group 7A (17) of the periodic table Forms a SALT when reacts with a metal (Example: NaCl) MOST HIGHLY reactive nonmetals because they have 7 valence electrons Gains 1 electron to become stable - 1 ions

Sublimation Sublimation- SOLID GAS without forming a LIQUID Example. Dry ice

Noble Gases on the Periodic Table Located in group 8A (18) of the periodic table Inert gases (Do not react) Outermost energy levels are full STABLE

Chapter 20 Section 3: Mixed Groups

You will learn how to…. Distinguish among metals, nonmetals, and metalloids Describe the nature of allotropes Recognize the significance of differences in crystal structure in carbon Understand the importance of synthetic elements This is important because the elements in mixed groups affect your life every day, because they are in everything from the computer you use to the air you breathe.

Metalloids Elements ABOVE and BELOW the zig-zag line (EXCEPTION: Aluminum (Al) Has properties of both METALS and NONMETALS

Boron Group

Carbon Group

Allotrope Allotrope- SAME element with a DIFFERNET molecular structure

Allotropes This figure shows three allotropes of carbon.

Nitrogen Group

Oxygen Group