Which of the following elements is not a metal?

Options

A. Calcium
B. Copper
C. Potassium
D. Sulphur

Explanation

To determine which of the following elements is not a metal, we need to analyze the properties of metals and identify the elements in question.

1. **Understanding Metals**: Metals are elements that are typically good conductors of electricity and heat, have a shiny appearance (lustrous), are malleable (can be hammered into thin sheets), ductile (can be drawn into wires), and sonorous (produce a ringing sound when struck).

2. **Identifying Elements**: We need to consider the elements provided in the options. Common examples of metals include calcium, copper, and potassium.

3. **Recognizing Non-Metals**: Non-metals do not exhibit the properties of metals. They are usually poor conductors of heat and electricity, are not lustrous, and are brittle in solid form. An example of a non-metal is sulfur.

4. **Conclusion**: Based on the properties and examples discussed, the element that is not a metal among the options is sulfur.

Thus, the answer is: **Sulfur** is not a metal.