Multiple choice

Which of the following is used as lubricants?

  1. Graphite

  2. Silica

  3. Diamond

  4. Iron oxide

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Graphite is an excellent lubricant because of its layered structure. The weak van der Waals forces between graphene layers allow them to slide easily over each other, reducing friction. Diamond is extremely hard, silica is abrasive, and iron oxide is rust - none serve as lubricants.