CH' 20 Elements

1
CH. 20 - Elements Their Properties

• List some properties of metals.
• Hard
• shiny
• good conductors of heat and electricity
• All metals are malleable and ductile
• Whats the difference between the two?
• Malleable means it can be rolled into sheets.
• Ductile means it can be drawn into wire.

2
Metals

• Alkali metals are elements in group 1
• There is one electron in the outer energy level
  of each element in group one.
• This means that the electron is given up when
  these elements combine with other elements to
  form a compound.
• Alkaline metals are elements in group 2.
• Each alkaline metal has two electrons in the
  outer energy level of each element.

3

• Strontium is used in fireworks with its bright
  red display.
• Magnesium gives cars, planes, baseball bats, and
  ladders a light weight, but strong structure.
• Calcium is needed in bones as CaCO3
• Barium is used in compounds in the medical field
  for x-rays.
• Radium is used in cancer therapy, but now other
  radioactive substances are used.

4
Transition Elements

• Transition elements are the metals in group 3
  through group 12 of the periodic table.
• They are less active then the metals in group 1
  and 2.
• What are the first elements of group 8, 9, 10?
  Iron triad.
• What are the elements in group 11?
• What are the elements in group 12?

5
Synthetic Elements

• What is a synthetic element?
• It is an element that can only be man made in a
  laboratory.
• Most synthetic elements occur after Uranium (92).
• All synthetic elements are highly radioactive and
  can be very harmful.

6
Nonmetals

• Nonmetals are to the right side of the staircase
  line on the periodic table.
• Most nonmetals are gases at room temperature.
• Nonmetals are poor conductors of heat and
  electricity.
• Hydrogen is the only nonmetal that is not right
  of the staircase.

7
Halogens

• Group 17
• All of the elements in this group have seven
  electrons in their outer energy level. These
  tend to be diatomic molecules.
• What is their charge?
• -1
• halogen means salt former
• when a halogen gains an electron from a metal it
  forms a salt.

8

• Fluorine is the most active element.
• Hydrofluoric acid is used to etch glass
• fluorine is used as an ingredient in toothpaste
• What is chlorine used for?
• Swimming pools as a disinfectant.
• Where is bromine used?
• It is a starch indicator
• it is the only nonmetal that is a liquid at room
  temperature.

9

• Iodine is a gray solid at room temperature.
• It is obtained from brine (shrimp).
• It is added in salt as iodized salt.
• This helps prevent goiters, which is the
  enlargement of the thyroid gland in your neck.
• When iodine is heated it turns directly to a
  purple gas. What is this called?
• Sublimation

10
Noble Gases

• Group 18 is the elements called noble gases
• These elements are stable their outer energy
  level is full.
• They are neither nonmetals or metals
• Noble gases are used in neon signs and laser
  light shows.

11
Metalloids

• What are metalloids?
• They have properties of metals and nonmetals.
• They are located right along the staircase line.
• Metalloids are semiconductors.
• B, Si, Ge, As, Sb, Te, Po, At are all
  metalloids.

12
Boron Group

• Boron is the first element in this group 13.
• Boron is used as an antiseptic laundry cleaner.
• Aluminum is the most abundant metal in the
  Earths crust.
• It is strong, but a light weight metal.
• What products can aluminum be found in?
• cans, foil, bats, ect.

13
Carbon Group

• Carbon is a nonmetal
• Which is more valuable graphite or diamond?
• Both are made up of the element carbon.
• The molecules in a diamond are arranged in a
  strong crystal structure, which makes it
  extremely hard. Its the hardest material.
• An element having different molecular structures
  is called an allotrope.
• Carbon makes up all organic compounds.

14

• Silicon is very abundant on the Earths crust as
  sand or SiO2.
• Tin is used to cover many metals to prevent
  erosion. It combines with copper to produce
  bronze and silver to produce pewter.
• Lead is a poisonous metal that was once used in
  gasoline and paint.

15
Nitrogen Group

• Group 15
• Nitrogen is the most abundant gas in the Earths
  atmosphere.
• Solid nitrates and ammonia (NH4) are used as
  fertilizers in soils for plant nutrients.
• Phosphorus is used in match heads and water
  softeners.

16
Oxygen Group

• Group 16
• You breathe in O2.
• O3 is used in the ozone to filter out ultraviolet
  light.
• Sulfur is a nonmetal used in paint pigments for
  color.
• Hopefully you now have an idea of where you use
  elements in your life.