Scientific Measurement

All measurements have a number value AND a unit.

Remember place values!

Significant figures are all the measurement numbers you can read from the markings on a measuring tool plus one guess.

The more numbers you can write for a measurement, the more precise the tool is.

This ruler shows does not show consecutive markings for the tenths. Our guess digit will be the tenths place.

How long is the pencil?

This is a beaker.It is not very precise.

How many mL of liquid are in the beaker?Hint: Where is the 10mL mark?

How many mL of solution are in this beaker?

This is an Erlenmeyer flask. It is not very precise.

What place value would your guess digit have?

This is tricky!How many mL are in the flask?

This is a graduated cylinder. It is more precise than an Erlenmeyer flask or a beaker.

Water-based solutions will form a meniscus in a graduated cylinder.

To read a volume you must be “eyeball to eyeball” with the meniscus.

Read the volume from the BOTTOM of the meniscus.

Read the volume in the graduated cylinder (mL).

How many mL are in this graduated cylinder?

This is a buret.

A buret is more precise than a beaker or graduated cylinder.

A buret has a meniscus.

The marks on a buret start with zero at the top. You read how much liquid left the buret.

Read the volume (mL) on the buret.