Page 121 - Innovator's Science-8

surface of the liquid called the meniscus. This way, you can measure
volumes of liquids precisely just like you learned to measure temperature

accurately with a thermometer.
The smallest volume that a measuring cylinder can measure depends on
the capacity of the measuring cylinder. Usually it is 0.1 mL in smaller

measuring cylinders with a capacity of 10 mL or 25 mL, it is 1 mL in a 100 mL
Science measuring cylinder, 2 mL in a 250 mL measuring cylinder, and 5 mL in a 500
Bytes
mL measuring cylinder. Suppose we want to take 70 mL of water. If we use a

Testimony 50 mL measuring cylinder, it would not be possible to measure 70 mL of
The meniscus is the water in one step. First, we have to measure 50 mL water and then 20 mL.
curved surface of a liquid
in a container. It forms Measuring volume in more than one step is not convenient. On the other
because of the a rac on hand, if a 250 mL or 500 mL measuring cylinder is used, the measurement
between the liquid and
the container's walls. can be done in one step but the accuracy would be reduced as the smallest
• For clean liquids like volume that these measuring cylinders can measure is greater than that of
water, read the bo om of a 100 mL measuring cylinder. Hence, a 100 mL measuring cylinder is the
the menicus.
• For coloured or opaque best choice for this measurement.
liquids, read the top of
the meniscus. Let Us Measure 50 Ml of Water
Reading at eye level When measuring a liquid using a measuring cylinder, first make sure the
ensures accuracy and
prevents parallax error, a cylinder is clean, dry, and placed on a flat surface. Carefully pour water into
common cause of it until it reaches the desired level. You can use a dropper to add or remove
incorrect measurements.
small amounts of liquid for accuracy. You'll notice that the surface of the
water is curved—this curve is called the meniscus. For clear liquids like
water, always take the reading at the
bottom of the meniscus, and ensure your
eyes are level with it to get a correct

measurement. For coloured liquids, take
Meniscus
the reading from the top of the meniscus.
Once your measurement reaches the mark

you need 50 mL. You can pour the liquid into
Pouring water into Measuring the reading the container you want to use.
the measuring cylinder
Determining Volume of Solid Objects with Regular Shapes
Collect various objects with a cuboid shapes, such as a notebook, a shoe

box, or a dice. Measure the length (l), width (w), and height (h) of the
objects using a scale. Suppose the length of the notebook is 20 cm, the
width is 15 cm, and the height is 3 cm. Calculate the volume by using the
following formula. Volume = l × w × h : = 20 cm × 15 cm × 3 cm = 900 cm .
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Record them in your notebook.

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