There are two chemical elements that begin with the letter Z: Zinc (Zn) and Zirconium (Zr).
Zinc is a metallic element with the atomic number 30. It is commonly used in galvanizing iron and steel to prevent rusting, and it is also an essential nutrient for humans.
Zirconium, with the atomic number 40, is a strong, malleable, and ductile metal. It is widely used in nuclear reactors due to its resistance to corrosion and its ability to withstand high temperatures.