Atomic weights are used to convert the mass of a sample into the number of moles of the element in the sample and vice versa. Four examples are provided for practice.

In this learning activity you'll explore the difference between mass and weight.

Learners read definitions of atomic symbols, atomic numbers, and mass numbers and then answer questions about the number of neutrons, protons, and electrons in select elements.

In this animated object, students are introduced to moles as a measurement.

In this interactive lesson, students examine the quantitative relationship between chemicals in a balanced mathematical equation.

In this learning activity you'll examine force, mass, and acceleration to understand this "Law of Acceleration."

Students identify the parts of a triple beam balance and practice measuring the mass of objects.

Learners examine the method used to calculate the mass percent of an element in a compound. Three examples and one problem illustrate the method.

Students use algebra to rearrange formulas and solve for the missing volume, density, or mass quantity.

Learners observe that the volume of one mole of any gas is 22.4 L at standard temperature and pressure. An illustration shows that only the mass of the molar volume differs with the identity of the gas.

Learners examine how chemists use moles to "count" atoms by weight. Examples are given.

Learners study the most common ways to measure fluid flow for industrial processes including absolute quantity, percentage, volumetric flow rate, and mass flow. A brief quiz completes the activity.

Students read how to determine and calculate the saturated density for a given sample of soil or aggregate, based on the mass-volume relationship. Practice problems complete the activity.

Learners follow a four-step process to determine the empirical formula of a compound from the masses of its constituent elements. The molecular formula is determined in a fifth step using the molecular weight of the compound.

Students read how to determine and calculate the dry density for a given sample of soil or aggregate based on the mass-volume relationship.

In this brief object, learners examine the direct relationship between the volume of a gas sample and the number of moles of gas. A problem is presented so students can test their knowledge of Avogadro's Law.