2. Atoms & Elements

At room temperature and standard atmospheric pressure, which phase(s) does H_2O exist in?

Which of the following elements is a liquid at room temperature and normal atmospheric pressure?

At room temperature, in which states of matter do the halogens exist?

In which phase are the molecules held rigidly together?

As you move down the periodic table to higher period numbers, what happens to the number of electron shells in the atoms?

In the periodic table, what do the rows (periods) indicate?

At room temperature, in which two states of matter do nonmetals commonly exist?

In a chemical equation, what does it mean when a substance is labeled with (s)?

Which of the following symbols is used to indicate that a chemical is in the gaseous state in a chemical equation?

Which element has the lowest freezing point among all substances?