metal and non metals - biology4you on rusting •rusting of iron - elementary science - youtube to...
TRANSCRIPT
Metal and Non Metals
Malleable Ductile Sonorous
Conductor Insulator
KEYWORDS
Rusting Brass
Calcium Chloride Galvanising Reactivity
Metals on the Periodic table Metals Non Metals
Metals and their properties
• Aluminium is light, strong and used to make aircraft.
• Copper is brown, a good electrical conductor and stretches easily. Used in electrical wiring.
Physical properties of metals
High density High melting point
Conduct Electricity
Malleable
Shiny (lustrous)
Ductile
Conduct heat
Hard and Strong
Sonorous
Physical properties of Metals
Malleable: can be hammered into shape
Ductile: can be stretched into wire (copper)
Sonorous: produce a ringing sound when struck
Physical properties of Metals
Shiny:
Conduct heat:
Conduct electricity:
Metals are good conductors of electricity
Some Exceptions
• Alkali metals (group 1) are soft with low densities.
• Mercury is liquid at room temperature.
Properties of Non Metals
• Usually liquids or gases
• Brittle (when solid)
• Low melting point
• Poor electrical conductors
• Poor heat conductors
Examples of Non metals
Exceptions of Non metal properties
• Carbon is a good conductor of electricity in the form of graphite.
• Carbon in the form of diamond is extremely hard with a high melting point.
Diamond Drill bit (very hard)
Video on Diamonds and Gold
• Diamond Mining in Sierra Leone – YouTube
• Raw Video: 507 Carat Diamond Found in S. Africa – YouTube
• Gold Divers - By The Numbers - YouTube
What is an alloys? • It is a mixture of metals.
NOTE: some metals are more useful when mixed with other metals.
Example: pure iron is quite brittle.
Iron mixed with carbon to produced steel.
Steel is much stronger and harder than iron.
Examples of Alloys
Alloy Composition Use Brass Copper + Zinc Muscial instruments
Ornaments
Bronze Copper + tin Statues
Examples of Alloys
Alloy Composition Use Stainless steel Iron + nickel + chromium Knives, sinks
New York Philharmonic Principal Brass Quintet play the UWS Apple Store - YouTube
Corrosion of Metals Rusting: the corrosion of metals
Metals react with air and water which causes them to corrode (rust)
Exceptions: gold and silver are very unreactive and remain shiny all the time.
Rusting
• Iron reacts with water and oxygen to form iron oxide (rust).
Iron + Oxygen Iron Oxide
Video on Rusting
• Rusting of Iron - Elementary Science - YouTube
To demonstrate rusting
• In order for rusting to occur, water and oxygen must be present.
To demonstrate rusting
To demonstrate rusting
To demonstrate rusting
Methods to Prevent Rusting
1) Painting
2) Galvanising (coat with zinc)
Removing Work from a Hot Dip Galvanizing Kettle - YouTube
Methods to prevent rusting
3) Greasing (coat with grease or oil)
Reactivities of metals
• Some metals want to lose electrons to have a full outer (very reactive).
• The metals in group 1 of the periodic table are the most reactive as they have only one electron on their outer shell.
To show that some metals are more
reactive than others:
To compare the reactivity of metals with water
• Calcium is the most reactive metal of all four.
To compare the reactivity of four metals with dilute acid.
• Calcium produces most bubbles, copper produces no
bubbles. • Calcium is most reactive and copper is not reactive at all
Hydrogen gas given off
Hydrochloric acid (HCl)
Video
• Ca,Zn,Cu+HCl.mpg – YouTube
• Metals with HCl - YouTube
Metals in decreasing order of rectivity
Calcium
Magnesium
Zinc
Copper
Decreasing Reactivity Increasing Reactivity
Metals in decreasing order of rectivity
Decreasing reactivity:
Calcium ---- Magnesium ---- Zinc ---- Copper
Increasing reactivity:
Copper ---- Zinc ---- Magnesium ---- Calcium
Exam Questions
Poster Project
• Where is the metal found?
• What are the properties of that metal?
• What it is used for?
• Is it used in an alloy?
• Images of metal
• Draw the bohr structure of your metal?
• Is your metal reactive?