There seems to be a misunderstanding in your question. You're asking about the properties of "Cl," which refers to the element chlorine (Cl). However, you're talking about the formation of sodium chloride (NaCl), which is a compound.

Let's break down the question and answer it correctly:

* Sodium chloride (NaCl) is formed when the elements sodium (Na) and chlorine (Cl) chemically react.

* The properties of sodium chloride are different from those of its constituent elements, sodium and chlorine.

Here are some properties of chlorine (Cl), the element:

* State at room temperature: Chlorine is a yellowish-green gas with a strong, pungent odor.

* Reactivity: Chlorine is a highly reactive element, meaning it readily forms chemical bonds with other elements.

* Toxicity: Chlorine is toxic in its gaseous form and can be harmful if inhaled.

* Uses: Chlorine is used in various applications, including:

* Water treatment: Chlorine is used to disinfect water, making it safe for consumption.

* Production of bleach: Chlorine is a key component in the production of bleach.

* Industrial processes: Chlorine is used in various industrial processes, such as the production of plastics, paper, and pharmaceuticals.

Let me know if you'd like to learn more about sodium chloride (NaCl) or chlorine (Cl)!