Metallic bonding Flashcards
What is metallic bonding
The electrons in the outer shell of metal atoms are delocalised and
so are free to move through the whole structure. The sharing of
delocalised electrons gives rise to strong metallic bonds. The
bonding in metals may be represented in the following form:
the delocalised electrons are attracted to the positive metal atoms
Properties of metallic bonds
Metals have free electrons available to move and carry charge throughout the metal lattice structure
Free electrons can also be called mobile or delocalised
Similarly, metals are also good conductors of heat
The delocalised electrons are free to move and can also carry thermal energy throughout the metal lattice structure
Metals thus have very high melting and boiling points and are solids at room temperature creates a strong electrostatic attraction
Why are Metals malleable
The layers of atoms in metals can slide over each other meaning metals are malleable and can be hammered and bent into shapes or rolled into flat sheets
Due to there regular structure
What are alloys
Alloys are mixtures of metals, where the metals are mixed together physically but are not chemically combined
They can also be made from metals mixed with non-metals such as carbon
Why are alloys stronger than pure metals
Alloys often have properties that can be very different to the metals they contain, for example, they can have greater strength, hardness or resistance to corrosion or extreme temperatures
Alloys contain atoms of different sizes, which distorts the regular arrangements of atoms
This makes it more difficult for the layers to slide over each other, so they are usually much harder than the pure metal
