An alloy is a mixture of two or more metals, or one metal and something that isn't a metal. They are mixed together so well you cannot tell that the alloy is not a pure metal. Alloys typically have very different properties to the components that went into making the alloys. Alloys are often much, much stronger than their individual components. Many tools and machines are made from alloys because they need to be strong.
You destroy something when you damage it so badly it is completely useless. You can destroy something by smashing it into tiny pieces, burning it or by dissolving it.
Hanoi is the capital city of Vietnam. It has a population of around 6.5 million.
Illinois, abbreviated to IL, is a state in the north east of the United States of America. The capital of Illinois is Springfield. The largest city in Illinois is Chicago.