Results

There are many different processes and phenomena that emit electromagnetic radiation. Humans have taken advantage of many of these processes to develop technologies that use electromagnetic radiation.

The beauty of a coral reef, the warm radiance of sunshine, the sting of sunburn, the X-ray revealing a broken bone, even microwave popcorn—all are brought to us by electromagnetic waves. The list of the various types of electromagnetic waves, ranging from radio transmission waves to nuclear gamma-ray (γ-ray) emissions, is interesting in itself.

Even more intriguing is that all of these different phenomena are manifestations of the same thing—electromagnetic waves (see Figure 15.1). What are electromagnetic waves? How are they created, and how do they travel? How can we understand their widely varying properties? What is the relationship between electric and magnetic effects? These and other questions will be explored.

Photoelectric materials emit electrons when they absorb light of a high-enough frequency.

Outcomes:

• Determine if a liquid is acidic, basic, or neutral
• Place acids or bases in relative order
• Describe on a molecular scale, with illustrations, how the water equilibrium varies with pH
• Determine concentration of hydroxide, hydronium and water at a given pH
• Relate liquid color to pH
• Predict (qualitatively and quantitatively) how dilution and volume will affect the pH and concentration of hydroxide, hydronium and water

This YouTube video investigates the structure and composition of the sun.

This online resource investigates the internal structure, outer layers and surface features of the sun.

These four short online lessons cover the following:

• What is the sun?
• Interior of the sun
• Outer layers of the sun
• Surface features of the sun