What are the 4 physical changes you can observe?

Why is it important that the polymer membrane in a PEM fuel cell allows only protons to move through it? It forces the electrons to move through an external circuit, where they can do work.

heat can be transferred by conduction and convection. which process do you think is quicker? why do you think so?

Suppose that from measurements in a microscope you determine that a certain bacterium covers an area of 1.50 pmº Convert this to square meters Express your answer in square meters. ishliste

A normal concentration of glucose, or sugar, in the blood is 95 mg/dl. how many grams of sugar would be present per liter of blood? show the conversion factors you use.

A material with the density of 2.7 grams/mL occupies 35.6 mL. How many grams of the material are there?

Where did the earth hold most of its original water

Giovanni created this chart to study for an exam. A 2-column table titled common ionic compounds. The first column labeled compound has entries sodium hydroxide (N a O H), iron oxide (F e O), calcium chloride (C a C l subscript 2), calcium carbonate

Consider the two electron arrangements for neutral atoms A and B. What is the difference between atom A and atom B? A - 1s22s22p63s1 B - 1s22s22p65s1 Atom B has lost some inner electrons.

Choose all the answers that apply. Which of the following has kinetic energy? rolling ball, moving car, book on a table, spinning top, or a falling tree.

Which of the following statements about the suns feature is true?