Which of these is an example of a physical change?

A. breaking bread

B. digesting bread

C. baking bread

D. toasting bread

For which of the following activities might you want to hire a chemist? testing a sample of water from a well finding a comet examining the structure of plant cells building a garage

Which of the following are formulations of the second law of thermodynamics? A. It isn't possible to transfer heat from an object at a lower temperature to another object at a higher temperature unless work is done. B.

How is a human egg is similar to a chicken egg

In most Acid-base reactions, what type of bond (ionic or covalent) is formed between the ions of the "salt"? What happens to the electrons in this sort of bond? Are they transferred, or shared?

A professor insists that a research scientist in her laboratory repeat an experiment, despite the fact that the experiment took several weeks to complete. Which best explains the professor's reasoning?

Which is the correct formula for phosphorus pentachloride? PCl4 because a subscript of 4 indicates four Cl atoms PCl5 because a subscript of 5 indicates five Cl atoms P5Cl because a subscript of 5 indicates five P atoms P5Cl3 because a subscript of

Why are the elements in groups 3 to 12 often used to make dyes?

What is not needed for corrosion of metals? a. oxygen c. water b. ions d. sunlight

What force can move the oceans

How many moles of NO3 are there in 6.2g