Metals and Structures

Flashcards about Metals and Structures based on lecture notes.

What are some general properties of metals?

High melting and boiling points, conduct electricity and heat, hard and dense, malleable, and ductile.

What holds metal atoms (or ions) together?

A 'sea' of electrons.

Why are metal atoms sometimes described as positive ions?

They donate electrons into the 'sea' of electrons.

What allows electricity to pass through solid metals?

The free electrons in the metal.

What happens when one end of a metal is made positive and the other end negative?

Electrons move towards the positive charge.

What can transfer heat quickly through metals?

Free electrons.

Why can layers slide over each other easily in a pure metal?

The atoms are all the same size, allowing layers to slide over each other easily.

What is created when atoms of different sizes are mixed with a pure metal?

An alloy.

How does adding a different sized atom to a metal affect the ability of its layers to slide?

The layers of atoms can't slide over each other as easily.

How does alloying affect the hardness and strength of a metal?

It becomes harder and stronger than the original metal.

What is an alloy?

A mixture of metals.

How are metals combined to form an alloy?

The metals are mixed together when they are molten.

Do metals react with each other when forming an alloy?

Metals never react with each other.

In Experiment 23.2, what do the rows of small bubbles represent?

Small bubbles in a dish represent the atoms in a metal and their close-packed structures.

In Experiment 23.2, what does injecting a larger bubble into the dish represent?

Adding an atom of a different metal.

In Experiment 23.2, how does the larger bubble affect the regular pattern of bubbles?

It disturbs the regular pattern of bubbles.

Layers of atoms can slide over each other easily in what type of metal?

Pure Metals.

What is a lot harder and stronger than the original metal?

Alloys.

What properties does alluminium provide in airplanes?

Low desity and strength.

What are airplanes made from?

Aluminium Alloys