🔍 Key Concepts

• Viscosity as a property of fluids (how easily a fluid flows) • Difference between how heavy an oil is versus how thick or resistant to flow it is • Meaning of S.A.E. (Society of Automotive Engineers) oil grades as a classification, not the property itself

💭 Think About

• Which choice best describes how much a fluid resists motion when it is being stirred, pumped, or sheared between surfaces? • Is viscosity directly about the oil’s weight, or about how it behaves when you try to move one layer of the fluid past another? • Look for the answer that describes what happens inside the oil when it moves, rather than a labeling or rating system.

✅ Before You Answer

• Be sure the option you choose describes a physical behavior of the oil, not just a rating system or label. • Confirm that the concept you select is tied to how easily layers of oil slide past each other. • Eliminate any option that refers mainly to external classification or unrelated properties like separation from water.