The CPI takes a constant basket of goods and sees how the price changes from year to year. If the price of the basket of goods increases, then there is price inflation. If the price of the basket of goods decreases, then there is deflation.
Copper and tin mainly make up bronze but other elements include phosphorus, manganese, silicon and aluminium.
Now, when copper is combined with other metals the end result is an alloy. Both bronze and brass are examples of copper alloys. They too play very important roles industrially. The primary difference between the two is that brass is made out of copperâs combination with zinc while bronze is literally copper plus tin. As mentioned, copper is now popularly used in many industries but for it to become more useful, it needs to be combined first with other more stable metals. This is because copper in its purest form is just too soft. This is the same reason why bronze and brass came to existence. Historically speaking, bronze is an older alloy because it is said that it was already discovered as early as 3500 BC.