Element 118 was reportedly synthesized in 1999, but the claim was later retracted. As a consequence of that experiment, element 116 was discovered. To what period and group would each of these two elements belong, and what known elements should each resemble?

Homogenized milk is composed of microscopic globules of fat suspended in a watery medium. Is homogenized milk a true solution (homogeneous mixture)? Explain.

Figure 11.27 on page 317 shows a photograph of chlorine, bro-mine, and iodine. Why should neither you nor the photographer attempt to take a picture of fluorine?

You are the supervisor in a car assembly plant where each car produced requires one body and four wheels. You discover that the plant has 200 bodies and 900 wheels. How many cars can be made from this inventory? (How does this problem fit in with the law of definite proportions?) 

Your friend has glasses with photochromic lenses; they darken and lighten as he goes outdoors and then back indoors. Explain to him that there is a lot of ionic chemistry going on inside the glass to cause the lenses to change.