Nature Of Science: Safety

1. Which of these is an example of an unsafe practice in a lab or classroom?

Testing a substance by tasting it

Watering a plant without wearing gloves

Using a glass rod to stir liquid in a glass beaker

Detecting an odor by moving air toward you with your hand

Testing a substance by tasting it is an example of an unsafe practice in a lab or classroom. This is because tasting a substance can lead to ingestion of harmful chemicals or toxins, which can cause serious health hazards. It is essential to use appropriate testing methods and equipment to ensure safety in a lab or classroom setting.

Explanation

Testing a substance by tasting it is an example of an unsafe practice in a lab or classroom. This is because tasting a substance can lead to ingestion of harmful chemicals or toxins, which can cause serious health hazards. It is essential to use appropriate testing methods and equipment to ensure safety in a lab or classroom setting.

2. During a scientific investigation, Max spills a few small drops of a chemical on his arm. Which of the following should Max do FIRST?

Put gloves on over his hands.

Rinse his arm with water and inform his teacher

Clean up the other spilled drops before anyone else is hurt.

Look in his notes to find out if the chemical was dangerous.

Max should rinse his arm with water and inform his teacher first because it is important to immediately remove any chemical substance from the skin to prevent further absorption or damage. Informing the teacher is necessary so that appropriate measures can be taken to ensure Max's safety and provide any necessary medical attention if required.

Explanation

Max should rinse his arm with water and inform his teacher first because it is important to immediately remove any chemical substance from the skin to prevent further absorption or damage. Informing the teacher is necessary so that appropriate measures can be taken to ensure Max's safety and provide any necessary medical attention if required.

3. Your lab group has completed the first of many water sampling activities. Empty sample bottles, pipettes, and microscope slides used during the activity remain on the lab counter. The best lab practice is to --

Wipe the glassware with paper towels

Leave the materials exactly where they are for the next sampling activity

Turn the sample bottles and pipettes upside down to drain and dry

Wash all the supplies with detergent, rinse thoroughly, and allow them todry

The best lab practice is to wash all the supplies with detergent, rinse thoroughly, and allow them to dry because this ensures that any residue or contaminants are removed from the glassware. Wiping with paper towels may not effectively clean the equipment and could leave behind particles or chemicals. Leaving the materials as they are could lead to contamination in the next sampling activity. Turning the sample bottles and pipettes upside down may help drain them, but it does not clean them. Washing with detergent, rinsing, and allowing them to dry ensures that the equipment is thoroughly cleaned and ready for future use.

Explanation

The best lab practice is to wash all the supplies with detergent, rinse thoroughly, and allow them to dry because this ensures that any residue or contaminants are removed from the glassware. Wiping with paper towels may not effectively clean the equipment and could leave behind particles or chemicals. Leaving the materials as they are could lead to contamination in the next sampling activity. Turning the sample bottles and pipettes upside down may help drain them, but it does not clean them. Washing with detergent, rinsing, and allowing them to dry ensures that the equipment is thoroughly cleaned and ready for future use.

4. Sarah’s lab group is trying to determine the identity of four unknown powders. Below are each student’s suggestions about how to test the powders.

Which student’s suggestion is the safest way to begin?

Sarah

David

Lena

Kesha

Kesha's suggestion is the safest way to begin because the question asks for the safest method. Without any specific details about the suggestions of each student, it is impossible to provide a more detailed explanation.

Explanation

Kesha's suggestion is the safest way to begin because the question asks for the safest method. Without any specific details about the suggestions of each student, it is impossible to provide a more detailed explanation.

5. Students were asked to observe pond organisms in a Petri dish. At the end of class, which of these is the MOST appropriate clean -up method?

Wipe the lab bench with a paper towel, and rinse hands with alcohol.

Wipe the lab bench with dry brush, and dry hands with a paper towel.

Wipe the lab bench with disinfectant, and wash hands with soap and water.

Wipe the lab bench with a paper towel, and wash hands with soap and water.

The most appropriate clean-up method is to wipe the lab bench with disinfectant and wash hands with soap and water. This is because disinfectant will effectively kill any potential pathogens or microorganisms that may have been present on the lab bench. Washing hands with soap and water is important to remove any remaining contaminants and ensure proper hygiene.

Explanation

The most appropriate clean-up method is to wipe the lab bench with disinfectant and wash hands with soap and water. This is because disinfectant will effectively kill any potential pathogens or microorganisms that may have been present on the lab bench. Washing hands with soap and water is important to remove any remaining contaminants and ensure proper hygiene.

6. While working in the lab, Shelia masses 20 g of sodium hydroxide on the triple beam balance then masses 20 g of sodium bicarbonate. Both are white powders but react to other chemicals in very different ways. Shelia is not certain which white powder is the sodium hydroxide. What should she do?

Place both powders in the trash and start over

Place a drop of water on a small amount of each powder and observe

Proceed with the experiment

Check with her teacher for guidance

Shelia should check with her teacher for guidance because she is unsure which white powder is sodium hydroxide. The teacher will have the knowledge and expertise to help Shelia identify the correct powder and provide guidance on how to proceed with the experiment. This is the best course of action to ensure accuracy and safety in the lab.

Explanation

Shelia should check with her teacher for guidance because she is unsure which white powder is sodium hydroxide. The teacher will have the knowledge and expertise to help Shelia identify the correct powder and provide guidance on how to proceed with the experiment. This is the best course of action to ensure accuracy and safety in the lab.

7. What does this symbol indicate about a chemical?

It can cause injury to body tissue

It is unstable in water

It catches fire easily

It is hazardous to the environment

The symbol indicates that the chemical can cause injury to body tissue. This means that if the chemical comes into contact with the skin, eyes, or any part of the body, it can cause harm or damage. It is important to handle such chemicals with caution and take necessary safety measures to avoid any injury.

Explanation

The symbol indicates that the chemical can cause injury to body tissue. This means that if the chemical comes into contact with the skin, eyes, or any part of the body, it can cause harm or damage. It is important to handle such chemicals with caution and take necessary safety measures to avoid any injury.

8. Mrs. Price reviewed the safety precautions for working with sharp objects. Which activity most likely requires following these safety practices?

Determining the mass of an empty beaker

Scooping 20 g of chemical powder from a storage container

Constructing a model of an animal cell

Viewing a stained slide with a microscope

Constructing a model of an animal cell most likely requires following safety practices when working with sharp objects. This activity may involve using tools such as scissors, knives, or blades to cut and shape materials for the model. Therefore, it is important to take precautions to prevent accidents and injuries, such as wearing gloves, using protective eyewear, and handling the sharp objects with care.

Explanation

Constructing a model of an animal cell most likely requires following safety practices when working with sharp objects. This activity may involve using tools such as scissors, knives, or blades to cut and shape materials for the model. Therefore, it is important to take precautions to prevent accidents and injuries, such as wearing gloves, using protective eyewear, and handling the sharp objects with care.