Elements and Their Properties Chapter 19

Section 1: Physical Properties of Metals Conduct heat and electricity Luster - reflect light well Malleable - can be hammered or rolled into sheets Ductile - can be drawn into wires High density High melting point

Chemical Properties of Metals NOTE: Metals usually have 1 to 3 electrons in their outer levels Metals easily lose electrons to the nonmetals by ionic bonding and become more chemically stable. Corrode easily (Example: silver tarnishing and iron rusting)

Physical Properties of Alkali Metals Soft Low melting and boiling points Low density Found in Group 1

Chemical Properties of Alkali Metals Highly reactive with oxygen and water; don’t occur naturally in elemental form Combine readily with other elements due to 1 electron in outer energy level

Discussion Why do metals conduct electricity? List 3 common properties of metals. Where are Metals found on the Periodic Table? Metals can form ionic bonds with ________. Alkali Metals can be found in what Group on the Periodic Table? How many electrons are in the outer shell of an Alkali Metal?

Alkaline Earth Metals Reactive, but less than Alkali metals Conduct electricity White and malleable 2 electrons in outer energy level Group 2

Transition Elements Can be found in Groups 3 through 12 on the Periodic Table Can have up to 32 electrons in their 2nd to last outer shell

Transition Elements They typically form colored compounds-(Ex: chromium found in rubies and emeralds) Good conductors of heat and electricity Iron triad - iron, cobalt, and nickel Iron - most widely used of all metals and main ingredient in steel; abundant in the Earth’s crust Cobalt and Nickel - used in some steels Nickel - used to coat other metals

Transition Elements 5. Copper, Silver, Gold - Coinage metals since once were commonly used in coins Copper - used in electric wiring because it is a superior electricity conductor Silver- used in photographic film and paper; jewelry Gold - used in jewelry 6. Zinc, cadmium, mercury - group 12 on the periodic table Zinc and cadmium - often used to plate or coat other metals Mercury - only room temperature liquid metal; used in thermometer and batteries

Study Questions: Section 1 (answer in your notes) Alkaline Earth Metals can be found in what Group on the Periodic Table? How many electrons do Alkaline Earth Metals have in their outer shell? The Transition metals are in what Groups on the Periodic Table? The elements that make up the iron triad are________?

The Inner Transition The Lanthanides - include lanthanum, cerium, praseodymium, amarium, europium, gadolinium, and terbium The Actinides - all are radioactive and unstable, uranium is the best known

Section 2: Properties of Nonmetals Usually gases or brittle solids at room temperature Not malleable or ductile Poor conductors of heat and electricity Not lustrous Ionic Compounds - form when nonmetals gain electrons from metals and become a negative ion Covalent Compounds - form when nonmetals share electrons with other non metals

Hydrogen Most common element in the universe Has a single electron…putting it in Group 1 in the periodic table A diatomic molecule - two atoms of the same element in a covalent bond Highly reactive element Found mostly on Earth in the compound water

The Halogens aka…”Salt Formers” Halogens are non metals A “salt forms” when a halogen gains one electron from a metal Have 7 electrons Group 17 in outer energy level and only needs 1 electron to complete this energy level Sublimation – the process of a solid changing into a gas without first becoming a liquid

The Halogens Halogens have many uses: Chlorine (most abundant halogen) - disinfectant and bleach Bromine - dyes in cosmetics Iodine - hormone regulation for thyroid Flouride-toothpaste Most halogen compounds are reformed from seawater

The Noble Gases Have 8 electrons in outer energy shell (full) Group 18 Not reactive with other elements Exist as isolated, stable gases Helium - used in blimps and balloons Neon, argon, krypton - used in lights

Discussion Questions Explain how solid metals are different from solid nonmetals. How can you tell that a gas is a halogen? What is the process of a solid changing directly into a vapor? Which element undergoes this process at room temp?

Answers 1. Explain how solid metals are different from solid nonmetals Solid nonmetals typically are nor ductile or malleable and do not conduct electricity. 2. How can you tell that a gas is a halogen? By their colors 3. What is the process of a solid changing directly into a vapor? Which element undergoes this process at room temp? Sublimation, iodine

Section 3: Mixed Groups Properties of Metalloids Have some metal and some nonmetal characteristics Form ionic and covalent bonds Have metallic and nonmetallic properties Partial conduction gives them semiconductors Located in Groups 13, 14, 15 ,16 & 17 (with the exception of aluminum)

Discussion Gaining & Losing While reacting: Nonmetals tend to gain electrons and obtain a negative charge Metals tend to lose electrons and obtain a positive charge

The Boron Group Group 13 Boron - used in water softening products, detergents, antiseptics, and fuels Aluminum - abundant in the Earth’s crust; used in cans, foil wrap, pans, building materials, and aircraft

The Carbon Group Group 14 4 electrons in outer energy level Examples Carbon - found in oil, coal, natural gas, and foods Germanium - also used in semiconductors Tin - used to coat other metals Lead - toxic, so no longer used in pain Diamonds, graphite, and buckminsterfullerene are all allotropes of carbon

Carbon Group cont… Silicon - an allotrope - same element with different molecular structures Silicon is found in sand. rocks, and soil The main component in semiconductors, which conduct electricity under certain conditions (EX: computer chips)

The Nitrogen Group Group 15 5 electrons in outer energy level Tend to form covalent bonds Nitrogen - used to make nitrates and ammonia Can be combined into compounds, such as amino acids Phosphorus - used in water softeners, fertilizers, match heads, fine china Antimony and bismuth used with other metals to lower their melting points

Questions What are allotropes? List one form of an allotrope.

The Oxygen Group Group 16 Oxygen - makes up 21% of air and is used by living things in respiration Nonmetal that exists as diatomic molecules (O2) Sulfur - used to form sulfides for pigment in paint Selenium - used in photocopies and multivitamins Tellurium and polonium are oxygen group elements

Synthetic Elements Synthetic elements- not usually found on Earth. Created by smashing existing elements with particles in an ion accelerator. Synthetic elements usually disintegrate quickly. Uranium can be made into neptunium which forms plutonium when it disintegrates Plutonium can be changed into americium, which is used in smoke detectors

Synthetic Elements cont… Transuranium elements have more than 92 protons and are synthetic and unstable The study of synthesized elements helps scientists to understand the forces holding the nucleus together Element 114 lasted for 30 seconds It combined 114 protons with 175 neutrons It broke apart due to enormous repulsion between protons