Matallic Bonding (pg 119) Flashcards
Metallic bonding involves what?
delocalised electrons
Do metals consist of a Giant Structure?
Yes
The electrons in the outershell of the metal atoms are delocalised, what do this mean?
They are free to move around. (delocalised)
There are strong forces of electrostatic attraction between the positive metal ions and the shared negative electrons.
What is ment by ‘Metallic Bonding’?
Forces of attraction hold the atoms together in a regular structure and are known as metallic bonding
Is metallic bonding very strong or very weak?
very strong
see diagram on page 119
What substances are held together by metallic bonding?
metallic elements and alloys (alloys are harder than pure metals)
is it the delocalised electrons in the metallic bonds which produce all properties of metals?
yes
What are most metals at room temperature? and why?
they are mostly solid at room tempertures
The electrostatic forces between the metal atoms and the delocalised sea of electrons are very strong, so need lots of energy to be broken. This means that most comounds with metallic bonds have a VERY HIGH melting and boiling points, so they’re generally SOLID at room temperature
Are Metals good conductors of heat and electricity? and why?
yes
The delocalised electrons carry electrical charge and thermal (heat) energy through the whole structure, so metals are good conductors of electricity and heat.
Most Metals are Mallable, what do this mean?
Malleable means that the metal can be bent or hammered or rolled into flat sheet.
(due to the layers of atoms in a metal they can slide over each other making metals malleable)
Are Pure Metals not right for certain jobs? and why not?
Pure metals often aren’t quite right for certain jobs as they’re often too soft when they’re pure, so they are mixed with ohter metals to make them harder
Most of the metals we use everyday are what?
alloys - a mixture of two or more metals, or a metal and another element.
Are Alloys harder than pure metals? and why/how?
Yes, alloys are harder than pure metal.
Different elements have different sized atoms, so when another element is mixed with a pure metal, the new metal atoms will distort the layers of metal atoms, making it more difficult for them to slide over each other.
This makes alloys harder than pure metal.
Copper is a metallic element. Describe and explain what property of copper makes it suitable for using in electrical circuits?
Copper is a good electrical conductor (1 mark), as it contains delocalised electrons which are able to carry an electrical charge through the whole structure (1 mark)
Suggest why an alloy of copper, rather than pure copper, is used to make hinges for doors?
Pure copper would be too soft to use as a door hinge, but alloys are harder than pure metal, so are suitable (1 mark)
