Final answer:
Iodine is the non-metal added to salt to prevent goiters.
Step-by-step explanation:
The **non-metal** that is added to salt to prevent **goiters** is **iodine**. Goiters are caused by the deficiency of iodine in the diet, and adding iodine to salt helps eliminate this concern. Iodine is an essential nutrient for the production of thyroid hormones, which regulate the growth and metabolism of the body.