To determine which element is the least malleable in its solid state, it is useful to consider the properties of the given elements. Malleability refers to the ability of an element to be deformed under compressive stress, such as hammering or rolling into thin sheets. Here is a brief analysis of each element:
1. Antimony (Sb): Antimony is a metalloid and, like other metalloids, has properties that are intermediate between metals and non-metals. While antimony is harder and more brittle compared to metals, it is not as malleable.
2. Phosphorus (P): Phosphorus is a non-metal and exhibits very low malleability. Non-metals, in general, are more brittle and do not exhibit the malleability characteristic of metals. Among the forms of phosphorus, such as white, red, and black phosphorus, none are noted for malleability.
3. Strontium (Sr): Strontium is an alkaline earth metal and metals in this group tend to be relatively soft and have fair malleability. It is more malleable compared to non-metals and metalloids like phosphorus and antimony.
4. Copper (Cu): Copper is a well-known metal with high malleability and ductility. It is extensively used for wiring and other applications where malleability is desirable.
Comparing these properties, the least malleable element among the choices given is phosphorus (P).
Therefore, the answer is:
Phosphorus (P).
