Performance Benchmark N.8.A.5
Students know how to use appropriate technology and laboratory procedures safely for observing, measuring, recording, and analyzing data. E/L
Research has shown that in order for the vast majority of students to truly develop a conceptual understanding of science they must be actively engaged in the “doing” of science. (SFAA 1996) “Science is a Verb” is a phrase that sums up the idea of students engaged in science. The traditional approach of lecturing to the students, telling them what they should “know” and what the big idea or concept is minimally effective for developing an understanding of science concepts. At best lecture may help some students “pass” the test, but will do little in the way of getting students to truly understand and apply concepts beyond the classroom setting or in weeks or years to come.
The Nevada State Standards place great emphasis on the students being able to safely “do” science, design and conduct experiments, make scientific observations and inferences, and use appropriate laboratory equipment in the course of their classroom science experiences. In order for students to meet the standards, they need to be allowed to engage in the science content being taught, explore the concepts, experiment with the purpose of learning about, not just “proving” it to be true. Students must be encouraged to explore the science concepts, make mistakes, and more importantly to learn from those mistakes in a safe, controlled and nurturing laboratory environment.
In order for students to make the most of laboratory experiences, they need to be familiar with common laboratory equipment, understand how to properly use theequipment, and how to record and communicate their results effectively.
Science Lab Ware
Students should have a working understanding of basic laboratory equipment. This understanding must go beyond knowing only the names of the pieces of equipment, it is importantthat students know how to properly use and care for the equipment. Science lab equipment often times looks similar, however, is used to perform specific tasks and is not interchangeable. Providing the students with adequate instruction and equipment, helps the students understand what and when to use a specific piece of lab ware. Although it is possible for students to be seriously injured if they do not use the appropriate equipment, it is more likely that they will collect inaccurate data making their findings unreliable.
Figure 1. Erlenmeyer flask.
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Figure 2. Graduated cylinder.
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Figure 3. Volumetric flask.
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Figure 4. Beakers
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Knowing how to correctly use a piece of equipment is as important as knowing when to use the equipment. Below are several common pieces of laboratory equipment with links on how to properly use them.
How to Read a Graduated Cylinder
Whenever a student needs to accurately measure the volume of a liquid they should use a graduated cylinder. There are several common sizes of graduated cylinders (10 ml, 25 ml, 50 ml, 100 ml, 250 ml, and 1000 ml).Which one to use is primarily based on the volume of the liquid being measured.The diameter of the cylinder may play a major factor in determining if it is the appropriate piece of equipment for the investigation.
Figure 5. The meniscus show in this picture is showing a volume of 6.8ml.
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For a brief explanation of how to properly read a graduated cylinder and for virtual practice visit, “Reading the volume from a Graduated Cylinder” - this web site gives a brief description of how to read the volume on a graduated Cylinder then provides several step by step tutorial sessions using a 10ml, 25ml, and 100ml cylinder.
To access these tutorials, visit
How to use a Triple Beam Balance
Students are often tasked with measuring the mass of an object. One of the more common tools to use is the Triple Beam Balance. This is a relatively inexpensive tool that is both sturdy and fairly easy to use once you know how to properly do so.
Visit Ohaus’ virtual Triple Beam Balance reading activity for a brief explanation of how to use and care for a Triple Beam Balance and a virtual activity that places an unknown mass on the balance and provides feedback on how accurately the riders were read.
To access this virtual lab and the related instructions, visit
Instructions on how to use and read a triple beam balance can be found at
How to use a Digital Balance
It is becoming more and more common for students to have access to digital balances, and although they are very simple to use there are a few finer points that the students should be aware of when using them. Download the pdf article “The Digital Balance” for a brief explanation on how to properly operate a digital balance. This article specifically addresses balances with draft shields but the information is general enough that it applies to the balances to which students typically have access.
To download the article, visit
Safety in the Science Classroom
Safety should be 1st and foremost in a teacher’s mind when they are guiding students through laboratory activities. One of the essential parts of any safety system is to ensure that the students are fully aware of how to use the laboratory equipment, what the safety rules and regulations are, where the appropriate safety equipment is located, and what to do in an emergency. It is not sufficient to simply teach a safety unit and expect students to apply these strategies at various points throughout the year. A prudent teacher will review the safety procedures before conducting any laboratory investigation or even performing a demonstration.
“Just In Time teaching” or the presenting of relevant information at the moment the students needit is a simple and effective method to help the student retain and utilize key concepts, instructions and safety rules and procedures. However to be effective, “Just In Time teaching” requires the teacher shift their paradigm and make a concerted effort to only present what is needed when it is needed and to resist the notion that if you are teaching “safety” you must cover every possible safety rule and regulation at one time, or in one “unit”. “Just In Time teaching” does NOT relieve the teacher of the responsibility of posting safety rules, reviewing relevant safety procedureas needed, monitoring and enforcing student behavior or maintaining a safe laboratory environment. It simply shifts when the information will be taught to a more relevant time thus increasing the likelihood that the students will retain and follow the rules and regulations.
Many potential accidents can be avoided by a well organized and planned laboratory experience. Such simple things as having the students work in cooperative groups were each has set responsibilities, one of which is to gather and return all supplies and equipment. By limiting the number of student who are allowed to gather the needed materials there is a reduced likelihood of accidental spills or breakage. In addition it is much easier for the teacher to monitor the distribution and return of the materials if they have to inspect or watch a few people rather than the entire class. In addition to limiting the number of students who can be up and moving around the room, arranging the room so that there is sufficient space to move from the desks/tables to the lab equipment or even sufficient room to simply move about the room is a big step in reducing tripping hazards. Setting up “traffic flow” patterns if the room is highly congested may be necessary to further facilitate student movement about the room.
There should be clear access to all safety equipment in the room. The students as well as the teacher should be able to move rapidly to the eye wash stations, as well as the fire extinguisher and spill cabinets. Students should be well drilled in how to evacuate the room in the case of a fire or other accident, and know what to do if the teacher is not able to lead the evacuation or call for help.
For comprehensive safety in the science classroom discussion, which contains additional information beneficial to the MS School teacher, see HS TIPS Benchmark N.12.A.4.
Safety Equipment
The need for a safe laboratory environment cannot be over stated. “Safety in the Science Classroom” is a Science Dissected article that addresses some of the basic classroom safety issues. To download this article, visit
Science Safety Contract,
Flinn Scientific has a MS Science Safety Contract that is comprehensive enough to address the needs of most MS Science teachers and students. It is highly recommended that teachers require students to not only sign but abide by the guidelines spelled out in this contract or a similar one. To access the Flinn MS Science Safety Contract visit,
Safe Use of Chemicals
Chemical safety in the science classroom is imperative. The failure to follow well established safety procedures has resulted in serious injury and death of both teachers and students. Despite the potential risk, using chemicals in a science classroom is not just necessary but should be a common occurrence when and where appropriate. The risks can be greatly minimized by monitoring the laboratory environment and enforcing the safety rules and procedures.
Oftentimes teachers who are not well-trained in chemistry are a bit intimidated when it comes to preparing chemical solutions and mixtures. The following section is designed to address some of the more common solution preparation situations.
How to Dilute Solutions
Improperly diluted acids can result in serious bodily injury. The following Science Dissected newsletter addresses how to properly dilute a solution. To download the article,go to
How to mix a “Known Molarity Solution”
Many chemistry activities require solutions of a known molarity, such as 1 M HCl, or 0.1 M HCl, in either case knowing how to safely mix a known molarity solution is a necessity. To download a Science Dissected article which provides a procedure for making known molarity solutions, see
How to “Make a Mass Solution by Percent”
Making a mass solution by percent is a common practice when using bulk chemicals that come in a dry form. The following Science Dissected newsletter explains how to make mass solution by percent and can be directly accessed at
Safe Handling of Chemicals
Students who are not use to dealing with bulk chemicals may have unsafe methods when scooping dry chemicals out of the supply container. Not only does it expose the students to potential risks, it increases the chances of cross contamination, wastedmaterials, and poor laboratory hygiene. Unsafe practices that lead to the needless exposure to chemicals must be brought to the students’ attention and corrected when they occur.
Goggles, Aprons and Gloves
The nature of the lab activity the students will be engaged in will determine what the appropriate safety equipment and clothing should be. If the students are dealing with any chemicals or with anything that could potentially pop/bounce/fling/shoot/fly into their eye then they should be wearing goggles or safety glasses. Gloves and aprons should be utilized with chemicals that are toxic or corrosive on contact or have the potential to stain or damage skin and/or clothing.
In addition to the basic safety clothing of goggles, aprons and gloves students should be expected to wear appropriate clothing during a lab activity. This includes such things as close toed shoes, long pants, and their hair should be restrained so that is cannot fall forward into the chemicals or equipment being used. The students should be provided with ample warning to dress appropriately for the upcoming activity.
In addition to taking precautions, so that accidents do not happen, it is imperative that the students know what to do if there is an accident. It is not sufficient to assume that the teacher will be able to direct the students on what to do during an emergency as there is always a chance that the teacher will be the one in need of emergency attention, not to mention the inherent degree of confusion that normally accompanies an emergency. With this in mind, students must be familiar with the operation and use of all relevant safety equipment, including the fire extinguisher, Eyewash and Body wash stations, fire blankets, fire alarm, spill control, and of course emergency exits.
Eye and body wash stations are typically very easy to operate, but knowing when to use them and how to properly use them may not be common knowledge, “How to use an Emergency Eyewash Station” is a brief but informative tutorial on when and how to use an eye wash station. To access this tutorial visit;
Note taking
Research has shown that an essential component of learning is for students to actively organize the information and record that information in a journal or notebook. The nature of science makes for a logical connection to the written organization of information. Ensuring that students keep an organized journal or notebook can be a challenge. Students often do not see the relevance or need to keep such a journal, nor invest the time and energy into keep it organized if the teacher does not place a value on an organized notebook. So, how can a teacher place enough value on this written record so that the students will not only “need” but “desire” to keep such a record? An effective way is to allow students to use their notebooks on quizzes and tests. By making the notebook a valuable resource to maintain, those students that are motivated by grades will attempt to keep an accurate and up-to-date document. Frequent journal checks that stress that students are maintaining their journals, and are held responsible for what is in them can increase the need to maintain a well organized notebook.
There are numerous ways to maintain a notebook, and although each has its strengths and weaknesses one key thing a teacher can do, is to be consistent in their expectations. Whether they insist on Cornel Notes, or a modified version of the AVID Interactive Notebook or some other style that they have found works for their students, the important thing is to ensure that the students are actively keeping a notebook and are consistently providing opportunities for the students to use their notebooks to do more than just record their notes.
For a brief description of “Interactive Science Notebooks” read the Science Dissected article of the same name. To download the article, go to
Technology in the Science Classroom
All too often when teachers think of “technology” they envision the newest computers, the latest probeware, the expensive Scientific Calculator, and although these are all examples of technology they are not the end-all and be-all of science. Computers and probeware can greatly increase not only the speed at which data is processed but also the amount of data collected. However, an increase in the amount of collected data does not in itself make for a better experiment. If the students cannot interpret data, nor come to some scientific conclusion based on the data, having more is of little or no use.
Another potential issue with the use of technology is that students “believe” that the data/numbers that they see on the screen are correct and accurate down to the last digit. This is especially true when it comes to the use of calculators in the classroom. Students often lack the number sense to understand that based on the tools that were using in the experiment, there is NO WAY you can possibly have a degree of precision to the ninth digit beyond the decimal point.
“Number Sense and the $100 Dollar Calculator” is a Science Dissected newsletter that addresses this very concern, and can be found at
For additional information on organizing items and effective use of notebooks see
MS TIPS Benchmark N.8.A.7
For further detail on students taking and maintaining permanent records and understanding scientific investigations seeHS TIPS Benchmark N.12.A.1
International System of Units (SI)
Teachers often express concern over the fact that the students seem to fail to grasp anything beyond the basics of the metric system. Although they understand that length or distance is measured in meters or some related unit depending on how big or small it may be, they often lack any reference to common objects and so do not know which unit is most appropriate to use. A potential cause for the students lack of a working understanding of metric units goes beyond the fact that metric units are not commonly used in the United States. It is the very way that metrics are taught to the students that exacerbates the problem. All too often teachers begin the year with an extensive “Metric Unit” where the students are challenged to measure the dimensions of a block of wood, calculate its volume and measure its mass. After conducting several of these types of activities they then may go several weeks without using these skills again. It is no wonder many students never seem to remember more than just the basics of the metric system. The extended delay from teaching to applying the skills, along with the fact that the activities that dominate the typical “Metric Unit” seem to have little relevance to the student’s daily lives makes it difficult to retain the information presented.