Think about the lab procedure you just read. Label each factor below V if it was variable during the procedure or C if it was constant.

Question

molecule size (large starch molecules vs. small glucose molecules)

material used as the membrane

amount of substances used

number of trials

whether the molecules diffused through the membrane (tubing)

Answer 1

Here's the labeling for each factor:

1. Molecule size (large starch molecules vs. small glucose molecules) - V (Variable)
2. Material used as the membrane - C (Constant)
3. Amount of substances used - C (Constant)
4. Number of trials - C (Constant, if the same number of trials is maintained throughout the experiment)
5. Whether the molecules diffused through the membrane (tubing) - V (Variable, as it depends on the size of the molecules and the properties of the membrane)

Adjustments might be made based on specific details of the lab procedure, but this is a general approach based on typical experimental setups.

Answer 2

Now label the variables: Molecule size is the
variable. The ability of the

material to diffuse is the
variable.

Answer 3

Based on your description, the labels for the variables would be as follows:

• Molecule size is the independent variable.
• The ability of the material to diffuse is the dependent variable.

In this context, the independent variable is what you manipulate (molecule size), and the dependent variable is what you measure (the ability of the material to diffuse).

Answer 4

Select all steps below that help you handle chemicals safely.

using droppers to transfer small amounts of chemicals

using tongs to move hot objects

checking the test tubes for chips prior to using them

washing your hands after you finish the lab

Answer 5

All the steps you mentioned help in handling chemicals safely. Here’s a breakdown:

1. Using droppers to transfer small amounts of chemicals - Safety Step
2. Using tongs to move hot objects - Safety Step
3. Checking the test tubes for chips prior to using them - Safety Step
4. Washing your hands after you finish the lab - Safety Step

Each of these actions contributes to maintaining a safe laboratory environment and reducing the risk of accidents or exposure to hazardous materials.

Answer 6

Select the reasons for checking glassware for cracks or chips prior to use.

Chips or cracks will make your experiment take longer.

You could cut yourself on glassware that has a chip.

Chips or cracks can make the glassware more likely to break during use.

Chips or cracks will change the outcome of the experiment.

Answer 7

The relevant reasons for checking glassware for cracks or chips prior to use are:

1. You could cut yourself on glassware that has a chip. - True
2. Chips or cracks can make the glassware more likely to break during use. - True

The other two statements are not typically valid concerns regarding checking glassware:

• Chips or cracks will make your experiment take longer. - This is not a direct safety concern or reason for checking glassware.

• Chips or cracks will change the outcome of the experiment. - While the integrity of glassware can influence experimental results, the primary focus of checking for safety reasons is to prevent injuries and avoid accidents related to broken glassware.

So, the first two options correctly explain why it's important to check for cracks or chips in glassware.