# Chapter 2: Measurement and Problem Solving

```Chapter 2: Measurement and Problem Solving
 Practice measuring according to
significant figures.

What is the volume of
cylinder in mL?

How many sigfigs is this?

How many L is this?

Express this number in sci.
notation.

Always take the measurement to one decimal place past
▪ Beakers/flasks/bottles /etc. are NOT used for measuring! Measure
the volume of liquids ONLY with a graduated cylinder
 Rulers

When using the electronic balance, record the entire
number on the screen
21.75 mL
2.65 cm

3.53 cm

The bathroom
scale has markings
at every 1 lb.
to the correct
number of digits.
 The unit system for
science
measurements,
based on the metric
system, is called the
International System
of Units or SI units.

The standard of length
 The definition of a meter, established by
international agreement in 1983, is the distance
that light travels in vacuum in 1/299,792,458 s.
(The speed of light is 299,792,458 m/s.)
 The standard of mass
 The kilogram is defined as the mass of a block
of metal kept at the International Bureau of
Weights and Measures at S&egrave;vres, France. A
duplicate is kept at the National Institute of
Standards and Technology near Washington,
D.C.

The kilogram is a measure of mass, which is
different from weight.
 The mass of an object is a measure of the quantity of
matter within it.
 The weight of an object is a measure of the
gravitational pull on that matter.
 Consequently, weight depends on gravity while mass
does not.
 The standard of time
 The second is defined, using an atomic
clock, as the duration of 9,192,631,770
periods of the radiation emitted from a
certain transition in a cesium-133 atom.
```