What is a primary use of metallic arsenic?

Metallic arsenic is primarily used in alloys, particularly with lead, which finds applications in car batteries. This is due to its properties that enhance the strength, durability, and performance of the lead alloy, making it suitable for use in the anodes of lead-acid batteries.

When integrated into lead, arsenic serves to improve the battery's resistance to corrosion and enhances its overall efficiency and longevity. This is especially important in the automotive industry, where long-lasting and reliable batteries are essential.

In contrast, other options provided focus on different applications: while arsenic compounds may be related to pesticides and glass production, the specific use of metallic arsenic aligns more closely with the production of lead alloys for batteries. The use in electronic components does not pertain directly to metallic arsenic, which is more relevant for its function in lead rather than electronic applications.