the electrons in the outer shell and delocalised. There are strong forces of electrostatic attraction between the positive metal ions and negative electrons which hold the atoms together in a regular structure
What is an alloy?
a mixture of 2 or more metals or a metal and another element.
Why are alloys harder than pure metals?
different elements have different sized atoms. So when an element is mixed with a metal the new metal atoms will distort the layers making it harder for them to slide over eachother
