How are the lungs kept free of germs and dirt from the air?

At stp what element is a good conductor of electricity?

The atomic number of a metal is ... A. 10 B. 11 C. 14 D. 20

Select the correct mass for each of the samples described below. 3.01 * 1023 molecules H2O 8.32 * 1020 formula units CaBr2 1.93 * 1026 molecules XeF6

As two chemicals react, the chemical bonds between the atoms in each react and break. Then, new bonds form. We call this process a chemical change or chemical reaction. True False

What compound has the ability to absorb large amounts of heat without itself increasing dramatically in temperature

What is unique about the way that transition metals form compounds? a. They don't form compounds c. They can form bonds with the electrons in the two outer-most shells b. They are the most reactive d. They can donate all of their electrons

What prompted rutherford to do the alpha particle scattering experiment?

How many moles of hydrogen would be required to produce 5.0 mol of water?

What is the biggest difference between an exothermic and endothermic process? A. The direction of energy flow. B. The amount of energy transferred. C. The type of energy being transferred. D. The speed with which energy is transferred.

The mass of 1 mol of chromium (atomic mass 51.996 amu) is