Unit 1 Test Version A

An experiment was designed to investigate the effect of caffeine on the heartbeat of water fleas. Two populations of water fleas were cultured. Both populations had water with the same mineral content, were supplied identical amounts of bacteria as food, and had their water temperature maintained at 20 degrees Celsius. Every two hours, the fleas from both populations were selected and their heartbeats were monitored. The fleas of population one had caffeine administered five minutes before their heart rate was checked. The fleas of population two were given nothing .What part of the experiment was the caffeine?

An experiment was designed to investigate the effect of caffeine on the heartbeat of water fleas. Two populations of water fleas were cultured. Both populations had water with the same mineral content, were supplied identical amounts of bacteria as food, and had their water temperature maintained at 20 degrees Celsius. Every two hours, the fleas from both populations were selected and their heartbeats were monitored. The fleas of population one had caffeine administered five minutes before their heart rate was checked. The fleas of population two were given nothing. What part of the experiment was population two?

An experiment was designed to investigate the effect of caffeine on the heartbeat of water fleas. Two populations of water fleas were cultured. Both populations had water with the same mineral content, were supplied identical amounts of bacteria as food, and had their water temperature maintained at 20 degrees Celsius. Every two hours, the fleas from both populations were selected and their heartbeats were monitored. The fleas of population one had caffeine administered five minutes before their heart rate was checked. The fleas of population two were given nothing. What part of the experiment was the heartbeat?

An experiment was designed to investigate the effect of caffeine on the heartbeat of water fleas. Two populations of water fleas were cultured. Both populations had water with the same mineral content, were supplied identical amounts of bacteria as food, and had their water temperature maintained at 20 degrees Celsius. Every two hours, the fleas from both populations were selected and their heartbeats were monitored. The fleas of population one had caffeine administered five minutes before their heart rate was checked. The fleas of population two were given nothing. What part of the experiment was the temperature?

An experiment was designed to investigate the effect of caffeine on the heartbeat of water fleas. Two populations of water fleas were cultured. Both populations had water with the same mineral content, were supplied identical amounts of bacteria as food, and had their water temperature maintained at 20 degrees Celsius. Every two hours, the fleas from both populations were selected and their heartbeats were monitored. The fleas of population one had caffeine administered five minutes before their heart rate was checked. The fleas of population two were given nothing. What part of the experiment was the food?

Solve & Round to Correct Sig Figs.4.5 + 4.32 =

A scientist in a research facility developed a procedure for a carefully controlled experimental procedure. The experiment is repeated several times and data is collected to reach a conclusion. What is the next step the scientist should take to make sure his conclusions are not biased?

A chemist wants to experiment to see which acid will neutralize drain cleaner the best. 50 mL of drain cleaner is poured into four different beakers. The pH is measured for all four samples. A different acid is added to each beaker. The pH is measured again. What is the independent variable?

The density of pure diamond is 3.5 g/mL. What is the volume of a diamond with a mass of 0.25 g?

Using the same balance, a chemist obtained the values 5.224 g, 5.225 g, and 5.226 g for the mass of a sample. These measurements have ___.

Three different people weigh a standard mass of 2.00 g on the same balance. Each person obtains a reading of 7.32 g for the mass of the standard. These results imply that the balance that was used is ____.

How many significant digits are in the following number? 0.002040

A mechanical pencil has a density of 3 grams per cubic centimeter. The volume of the pencil is 16.2 cubic centimeters. What is the mass? (Make sure your answer reflects sig figs and units.)

The density of lead is 11.342 g/mL. What would be the volume of a 150.0 g piece of lead? (Make sure your answer reflects sig figs and units.)