Acar traveled 60 km in 2 hours, 84 km in the next 1 hour, and then 68km in 2 hours before reaching its destination. what was the cars average speed?

Achemistry student needs of 40ml diethylamine for an experiment. by consulting the crc handbook of chemistry and physics, the student discovers that the density of diethylamine is 0.7 . calculate the mass of diethylamine the student should weigh out. round your answer to significant digits.

Achlorine atom has 17 protons and 18 neutrons. what is its mass number? what is its atomic number?

How does an observation about an object differ from an inference about that object