Recalling the You Tube video embeded in your lectures and the following image, which particular volcanic hazard is presented below: 

You perform an experiment in which you take 16 pots (same size) of strawberry plants and give half of them 10 ml of nitrogen supplement per liter of water and the other half receive only water. Each group is then exposed to 16 hours of light each day. You monitor the height of the plants for 4 weeks. You observe that plants given nitrogen supplement grow taller than plants grown with no nitrogen supplement. What is the independent (experimental) variable in this experiment? 

Beth was monitoring the oil spill into the Gulf of Mexico from an oil tanker. From her observations, she noted that the oil was moving as large patches in the water. It did not appear as though the oil was dissolving into the water. Why did the oil not dissolve into the water?

Which of the following functional groups is present in nucleic acids but not amino acids?

In water, some molecules separate to produce equal amounts of hydrogen and hydroxide ions that can reassociate with each other. Therefore, the pH of pure water is:

A suggested explanation for a natural event that can be tested using the process of science is known as a

Bicarbonate ions in the blood can absorb hydrogen ions, keeping pH balanced.  Bicarbonate is acting as a(n) ________ in blood.

According to the chapter “The Market Revolution, which of the following had the greatest impact on the spread of slavery?

According to the chapter “Democracy in America,” Andrew Jackson’s background differed from previous American presidents for which of the following reasons?

According to the chapter “Democracy in America,” the Nullification Crisis occurred over political disagreements about which issue?