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.

In this learning activity you'll examine the difference between two types of interactions with customers, encounters and relationships.

In this interactive object, learners calculate formula and molecular weights by working through five examples and two problems.

In this well-illustrated activity, learners examine the three types of intermolecular forces: dipole-dipole forces, London or Van der Waals forces, and the hydrogen bond. Two interactive questions are included.

Learners calculate gas density from the standard molar volume and observe how the density increases with the increasing molecular weight of the gas.

In this animated object, learners examine neutral fats, phospholipids, and cholesterol. The molecular formula and general function for each are shown.

At the end of this lesson you will be able to

- Explain what biosecurity means.

- Describe why biosecurity is important.

- Identify what kinds of disease agents we try to prevent or control with biosecurity.

- Demonstrate disease agent-host-environmental interactions that result in disease.

In this well-illustrated object, learners examine the structures and properties of the four types of solids: molecular, metallic, ionic, and covalent network. Five interactive questions are provided.

This screencast shows how blood droplets are held together by a strong cohesive molecular force that produces surface tension in each drop and on the external force. Surface tension pulls the surface molecules of a liquid toward its interior, decreasing the surface area and causing the liquid to resist penetration.

In this animated object, learners examine neutral fats, phospholipids, and cholesterol. The molecular formula and general function for each are shown.