Question

place the following atoms in order of increasing reactivity top (lowest) to bottom (highest): argon, silicon, sodium, chlorine

Explanation:

Step1: Recall noble - gas stability

Argon is a noble gas with a full outer - electron shell, so it has very low reactivity.

Step2: Consider non - metal reactivity trends

Silicon is a metalloid and is less reactive than non - metals in the same period that are closer to filling their outer shells.

Step3: Analyze non - metal reactivity

Chlorine is a non - metal and is highly reactive as it only needs one electron to complete its outer shell.

Step4: Analyze metal reactivity

Sodium is a metal and readily donates its outer - shell electron. In the context of these elements, metals are generally more reactive than metalloids and noble gases, and among these, sodium is very reactive.

Answer:

Argon, Silicon, Chlorine, Sodium