Science Tool Practice –

Triple Beam Balance

The triple beam balance is a science tool that is used to measure mass. Mass is how much “stuff” is in an object. In science, we measure mass in grams (metric system). A gram is about the same as a “paperclip” in mass.

milligram / centigram / decigram / gram / dekagram / hectogram / kilogram
1/1000 / 1/100 / 1/10 / Base unit / 10 x / 100 x / 1000 x

Directions:

  1. Set the balance on a level surface. Make sure that the sliders are pushed all the way to the left. (sliders are the weights on the 3 beams). With nothing on the pan, check to see if the mark levels out at zero. If it does not level out at zero, ask your teacher for help in calibrating the balance.
  2. Place the object to be measured on the pan. (the pan is the flat metal surface of the balance)
  3. START by using the LARGEST slider. Move it to the right until the line goes below zero. When the line goes below zero, MOVE BACK one notch with the large weight. (the large weight represents 100g)
  4. NEXT, move the medium slider to the right until the line goes below zero. Back up one notch with this weight. (the medium weight represents 10g).
  5. FINALLY, move the small slider to the right until the line becomes level with zero.
  6. Add the total of each of the sliders together to get the total mass. Your total is in grams. You may have a decimal.
  7. Repeat for each object measured.

IMPORTANT HINTS –

  1. The slider weights MUST be in a “notch”. Do not put them in between notches. Your measurement will be wrong.
  2. Only the small slider may be left in between numbers. This will help to be more exact.
  3. Always store your balance with the slider weights all the way to the right. Cover when finished. Treat the tool with care. Do not drop the balance.

Practice – You will receive three objects to measure. Take turns with your group and carefully measure each object following the steps listed above. Record your answers on your record sheet.

Name ______Tools Practice Record Sheet Class Period ______

RECORD SHEETName______Class Period ______

Triple Beam Balance Station

Fill in the blanks using the information at this station.

1. In science, we measure mass of an object in ______. (unit)

2. A gram is about the same as the mass of one ______.

Object (write the name) / Mass (g)
1.
2.
3.

Microscope Station

After reading over the information at this station, answer the following questions:

1. You should carry the microscope with ______hands.

2. Keep your fingers off the ______.

Label the parts of the microscope below.

A ______B______

C______D ______

E______F______

G______H______

I______J______

K______

GRADUATED CYLINDER PRACTICE STATION

Information:

A graduated cylinder is used to measure out volume of liquids in milliliters. The cylinders are “graduated” or marked off in equal units. Not all the lines on a graduated cylinder are marked with a number – this means that you MUST determine what each line on the cylinder stands for by figuring out the scale.

Look at cylinder number 1. Only the 100 lines are marked, but there are marks between the lines. If there are 5 spaces between each numbered mark, then how much does each mark on this cylinder stand for? 100 divided by 5 = 20 Each space marked on this cylinder stands for 20 milliliters. How much liquid is in this cylinder? 400 + 20 + 20 = 440 mL

To figure the scale, find the milliliters between the numbered lines (what is it counting by), divide by the number of spaces between the numbered lines to find what each space is worth.

What is a meniscus?

When you are looking at liquid in a glass or plastic cylinder sometimes the top line of the liquid does not appear to be straight across. This “non-straight” line is called a “meniscus”. Look at the example below:

The rule in science is to read the measurement from the CENTER. If the meniscus is concave, read from the bottom. If the meniscus is convex, read from the top. Liquids, such as water, tend to cling to the edges of the container to form a concave meniscus. Liquids, such as mercury, tend to cling to each other which make a convex meniscus.

Just remember to read from the CENTER of the substance.

Helpful hint – Choose a graduated cylinder that has the most exact measurement and will hold the amount of liquid that you are using.

Graduated Cylinder Station

1. Graduated cylinders are used to measure ______of liquids in ______. (unit)

2. What do you call the “non-straight” line that appears at the top of what you are measuring in a graduated cylinder?

______

3. When there is a meniscus, you should measure from the ______of the line.

How much liquid in the following examples?

What would be the best correct

measurement for the liquid in this cylinder?_____