chapter 12 elements and their properties
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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. - PowerPoint PPT PresentationTRANSCRIPT
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 BondingWhat is a Metallic Bond?- A metallic bond occurs in metals. A metal consists of positive ions surrounded by a “sea” of mobile electrons.
Name 4 Characteristics of a Metallic Bond.
1. Good conductors of heat and electricity
2. Great strength
3. Malleable and Ductile
4. 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
– 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)