Which of the following is a characteristic of a mixture? a. it has varying properties. b. it has a fixed composition. c. it only contains pure substances. d. it has both varying properties and a fixed composition?

In a vernier instrument the main scale is in 1/2 mm divisions .vernier is made by redividing 19 such divisions into 20 equal parts. calculate the least count of the instrument.

Examine the equation. 23490th→23088ra+42he what kind of barrier would you need to block the radioactive particles from this reaction? a. a piece of paper b. a sheet of aluminum foil c. a two-inch block of lead d. a solid concrete block

Why are graphs useful when interpreting data