Chapter 12 Elements and Their Properties

Objectives 12.1 Describe the properties of a typical metal 12.1 Identify the alkali and alkaline earth metals 12.1 Differentiate between three groups of transition elements

Minor Objectives 12.2 Distinguish among elements classified as lanthanides, actinides, and transuranium elements 12.2 Determine the uses of transuranium elements 12.2 Compare the pros and cons of making new elements

Objectives 12.3 Recognize hydrogen as a nonmetal 12.3 Compare and contrast properties of halogens 12.3 Describe properties and uses of noble gases

Objectives 12.4 Distinguish among metals, nonmetals, and metalloids 12.4 Describe the nature of allotropes 12.4 Recognize the significance of differences in crystal structure in carbon

Metallic Bonding Name 4 Characteristics of a Metallic Bond. What is a Metallic Bond? - A metallic bond occurs in metals. A metal consists of positive ions surrounded by a “sea” of mobile electrons. Good conductors of heat and electricity Great strength Malleable and Ductile Luster This shows what a metallic bond might look like.

Definition of Words Malleable: Bendable, can be hammered to be thinner or rolled up in sheets Ductile: Stretchable, can be pulled apart like laffy taffy Luster: Reflects light, looks shiny

Alkali Metals Highly Reactive, not found in nature by themselves First column (one word) Highly Reactive, not found in nature by themselves React with Water Lose 1 Electron

Alkaline Earth Metals Second Column (Two words) Some are found in nature by themselves (Top of column) such as Magnesium Not as reactive as the Alkali Metals Lose Two electrons Calcium: Bones Magnesium: Muscles (as well as bones)

Transition Metals Less reactive than other metals to left. General Rule for metals is closer to bottom left, more reactive Important sections include Iron Triad, Coinage Metals

Iron Triad Iron, Cobalt, Nickel Only common metals known to create a magnetic field Iron second most abundant element among metals in crust Aluminum is first

Coinage Metals Copper, Silver, Gold Very unreactive, which leads to be being able to be used as money These also are the best conductors out of all the metals Silver > Copper > Gold Silver plays role also in photography

Other notables Zinc and Cadmium: Used to coat other metals for protection from rust (They do rust, but maintain good strength) Mercury: Liquid metal at room temperature, poisonous

Metals in the Crust Oxygen 47% Silicon 28% Aluminum 8% Iron 5% Calcium 3.6% Sodium 2.8% Potassium 2.6% Magnesium 2.1%

12 -2 Transuranium Elements Uranium is largest atom that exists naturally (92 Protons) Elements beyond Uranium are synthetic (made in laboratory) Smash elements together at super speeds to collide and hopefully fuse Is it worth it? They hope so, you may disagree.

12-3 Non-Metals Properties of Non-Metals Dull, Brittle, Powdery Non-Metals alone tend to be gases at room temperature Tightly Held Electrons Can form ionic or covalent bonds

Hydrogen Most abundant element in universe (75 – 90%) depending on what you read Number continues to drop… via fusion A non-metal which tends to be fairly reactive (flammable, central to the role of acid/base) Diatomic Di means 2 atoms. Hydrogen Gas means 2 Hydrogens bound Dr. HOFBrINCl (all of the diatomic)

Halogens “Salt Makers” Have 7 valence electrons, exist diatomically Very reactive (Flourine most) Uses include: Etching glass, cleaning pools, keeping water safe, dyes (including lipstick), and warfare

Noble Gases Name comes from nobles not hanging out with the common folk. Full outer shell. Inert (Unreactive) Used in locations of high heat, light bulbs, blimps, storage of reactive elements

Boron’s Column Many are semiconductors (used by computers) Aluminum is used all over the place (most abundant metal in crust) Boron used in eyewash (boric acid) and water softeners

Carbon Group Carbon: Basis of organic life (the definition of organic – does it have carbon?) Allotropes – Same element, different molecular structures Carbon has many – graphite, diamond, fullerenes, coal Silicon – Sand component Lead – poisonous, used in ancient rome/paints

Nitrogen’s Group Nitrogen makes up 80% of atmosphere Nitrogen – needed by plants (not in gas form, nitrates) as fertilizer Phosphorus – Matches (as well as fertilizer) Allotropes – Red and White matches

Oxygen’s Group Similar properties to halogens Oxygen 20% of atmosphere Allotropes – oxygen and ozone Sulfur – Used in paints (pigments) and battery acid (Sulfuric acid)