An alloy of copper and tin is:

**The reasoning** Let's break down common alloys by their base metals: **Bronze** = Copper + Tin. This is the classic combination used for thousands of years to make tools, weapons, and sculptures. The tin makes copper harder and more durable. **Brass** = Copper + Zinc (not tin!). It's yellowish and used in musical instruments and door fittings. **Steel** = Iron + Carbon. No copper at all. **Solder** = Typically Lead + Tin (older types) or Tin + other metals. Used for joining metals together. The question specifically asks for copper + tin, which is **Bronze**. **Why the wrong options tempt you** - **Brass** looks similar to bronze and also contains copper, but it's copper + *zinc*, not tin - **Steel** is super common, so students might guess it without thinking about the metals involved - **Solder** contains tin (half correct!), but it's usually with lead, not copper **Quick takeaway** Remember: **Bronze = Copper + Tin** (both end in 'n' if that helps!). Brass swaps the tin for zinc. This distinction appears in Chemistry, Physics, and even some Technical Drawing questions!