1. Chapter 7
The Elements

2. I. Properties of s-Block Elements
A. Representative Elements
Groups 1A through 8A
Display a wide range of physical and chemical properties

3. - Metals and nonmetals - Highly reactive and some that hardly react - Solids, liquids, and gases at room temperature

4. B. Hydrogen
Share more properties with the nonmetals of group 7A than of group 1A
Has both metallic and nonmetallic properties so it is not considered part of any group
Burns when ignited with air
- Hindenburg crashed in 1937 in New Jersey

5. Colorless, orderless, lighter-than-air gas
Three natural occurring isotopes
1. protium: hydrogen-1 (99.985%)
2. deuterium: hydrogen-2 (0.015%)
3. tritium: hydrogen-3 (radioactive)

6. C. Group 1A: Alkali Metals
React with water to form alkaline, or salt, solutions
Easily lose a valence electron and form an ion with a 1+ charge
Soft enough to cut with a knife
Stored in oil to prevent a reaction with oxygen in the air
Good conductors of heat and electricity

7. 1. Lithium
Least reactive of alkali metals
Used for long lasting batteries and as a drug to treat bipolar disorders

8. 2. Sodium and Potassium
Most abundant alkali metals
Must have in our diets because many biological functions are controlled by sodium and potassium ions
- Carries nerve impulses along the cell

9. D. Group 2A: Alkaline Earth Metals
Form compounds with oxygen, called oxides
Shiny solids
Lose their two valence electrons to form ions with a 2+ charge

10. 1. Calcium
Essential in maintaining healthy bones and teeth
Found combined with carbon and oxygen in calcium carbonate
- Main ingredient in limestone, chalk, and marble
Used as an antacid

11. 2. Magnesium
Plants cannot function without a supply of magnesium because each chlorophyll molecule contains a magnesium ion
Your body needs magnesium in muscle function and metabolism
Results in hard water when found in the water supply

12. II. Properties of p-Block Elements
Metals, metalloids, and nonmetals
Solids and gases

13. A. Group 3A: The Boron Group
Always found combined with other elements in nature
B, Al, Ga, and In lose 3 valence electrons to form ions with a 3+ charge

14. 1. Boron
Can withstand extreme differences in temperature without shattering
- Good for laboratory equipment and cookware
Borax, a cleaning agent and as fireproof insulation
Boron nitride is the second hardest known material, only diamond is harder

15. 2. Aluminum
Third most abundant element in Earth’s crust
Found combined with oxygen and requires a great deal of energy to remove it from oxygen
- Cost effective to recycle aluminum products

16. 3. Gallium
Used in thermometers because it literally melts in your hand
Used in solar panels because it produces an electric current when it absorbs light

17. B. Group 4A: The Carbon Group
Wide range of properties limits the rules that apply to all members of the group

18. 1. Carbon
Whole branch of chemistry devoted to the study of carbon compounds – organic chemistry
Inorganic chemistry includes carbonates, cyanides, carbides, sulfides, and oxides
Two allotropes – graphite and diamond
- Allotropes are forms of an element in the same physical state – solid, liquid, or gas – that have different structures and properties

19. 2. Silicon
Used in computer chips and solar cells
Found combined with oxygen in silicon dioxide which is found in quartz, sand, and glass

20. 3. Lead and tin
Lead is toxic and no longer used for eating utensils, pipes for plumbing, as an additive in gasoline, or in paint
Tin is a very soft metal
Tin
Lead

21. C. Group 5A: The Nitrogen Group
Colorless, ordorless, gas
Makes up about 78% of Earth’s atmosphere
Liquid ammonia is used in cleaning supplies
Fertilizers are made with nitrogen

22. 2. Phosphorus
Three solid allotropes
Red phosphorus is used on the striking surface of matchboxes
No longer used in fertilizers because they are harmful to the environment i.e. cause excess algae in lakes

23. 3. Arsenic, Antimony, and Bismuth
Arsenic is toxic
Antimony can be shaped and cast in molds to make tableware
Bismuth is an active ingredient in Peptobismol

24. D. Group 6A: The Oxygen Group
Tend to gain two electrons to form ions with a 2- charge
1. Oxygen
Has two allotropes
Ozone (O3) is an unstable gas
Oxygen gas (O2) makes up 21% of Earth’s atmosphere

25. 2. Sulfur
Has ten allotropes
Ingredient in fertilizers, steel, papers, and paints

26. 3. Selenium
Found in fish, eggs, and grains
Works with vitamin E to prevent cell damage
Found in locoweed which can sicken livestock
Used in solar panels to convert light into electricity

27. E. Group 7A: The Halogens
“Salt formers”
Reactive nonmetals that are always found combined with other elements in nature
Tend to gain one electron to form ions with a 1- charge

28. 1. Fluorine
Most electronegative element on the periodic table
- Has the greatest tendency to attract electrons
- Reacts with every element except helium, neon, and argon
Added to toothpaste and drinking water to protect tooth enamel from decay

29. 2. Chlorine
Used to disinfect sewage and as a bleaching agent
Hydrochloric acid in your stomach helps you digest food

30. 3. Iodine
Body needs iodine to maintain a healthy thyroid gland to help control growth and metabolic rates
Iodine tablets are used to disinfect water

31. F. Group 8A: Noble Gasses
Colorless and unreactive
Known for their stability

32. 1. Helium
Lighter-than-air gas
Used in blimps, airships, and balloons
2. Neon
Used in light displays
- Produces an orange light when its excited electrons return to lower energy states

33. 3. Argon and Krypton
Argon makes up 1% of Earth’s atmosphere
Both are used in incandescent light bulbs

34. III. Properties of d-Block Elements
Transition metals
Labeled “B”
Any element whose final electron enters a d sublevel
Differ in physical properties

35. A. Formation of ions
Can lose two s electrons to form an ion with a 2+ charge
Elements with unpaired d electrons can form ions with a 3+ or higher

36. B. Magnetism
Ferromagnetism is a strong attraction of a substance to a magnetic field
- Ions align themselves to the direction of the field
- Iron, cobalt, and nickel can form permanent magnets

37. Diamagnetism is when a substance is either unaffected or slightly repelled by a magnetic field
- Element’s electrons spin in opposite directions, causing their magnetic fields to cancel out

38. C. Sources of transition metals
Copper, silver, gold, platinum, and palladium are the only transition metals stable enough to be found in nature uncombined with other elements
Most others are found as compounds with nonmetals in ores that can be mined and extracted

39. D. Uses of transition metals
Many are found in alloys used to make items such as jet engines, drill bits, surgical instruments, and armor
Many are trace elements needed by your body
Some are included in vitamin and mineral supplements

40. IV. Inner Transition Metals
Any element whose final electron enters an f sublevel
A. Lanthanide series
Elements from period 6 are named the lanthanide series because they follow the element lanthanum

41. Silvery metals
Found mixed together and are hard to separate
Neodymium and praseodymium absorb high-energy radiation so they are used in welder’s goggles
Yttrium and europium are found in television screens and computer monitors

42. B. Actinide series
Elements from period 7 are named the actinide series because they follow the element actinium
Radioactive elements
Three exist in nature, the rest are synthetic