Elements and Their Properties

1. Elements and Their Properties Chapter 19

2. 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

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

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

5. 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

6. 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?

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

8. 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

9. 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

10. 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

11. 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________?

12. 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

13. 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

14. 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

15. 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

16. 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

17. 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

18. 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?

19. 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

20. 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)

21. DiscussionGaining & Losing While reacting: • Nonmetals tend to gain electrons and obtain a negative charge • Metals tend to lose electrons and obtain a positive charge

22. 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

23. The Carbon GroupGroup 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

24. 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)

25. The Nitrogen GroupGroup 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

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

27. 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

28. 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

29. 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