What is the alloy of copper and zinc known as? 

Brass 

The correct answer is option 1. Brass.

The alloy of copper and zinc is known as brass. Brass is an alloy composed primarily of copper (Cu) and zinc (Zn), although other elements may also be included in smaller quantities. The proportion of copper to zinc can vary, resulting in brasses with different properties. Brass is valued for its attractive gold-like appearance, ease of machinability, and corrosion resistance. It finds wide applications in areas such as musical instruments, decorative items, plumbing fixtures, and fittings. So, the correct answer is: Brass.