5.3 Mass & Volume

5.3

Mass: the amount of matter in an object Measured using metric units (grams or

kilograms) You can use a pan balance to measure mass Which block has more mass?

Mass and weight aren’t the same Weight is the measure of gravity’s pull on

you▪ Your weight on the moon is 1/6 your weight on Earth

▪ How much would someone weigh on the moon if they weighed 120 pounds on Earth?

▪ It doesn’t matter if you are on the Earth or the moon, your mass stays the same

Volume: the amount of space taken up by an object You can measure the volume of solids,

liquids, and gases▪ V = length × width × height▪ V = 5 cm × 4 cm × 3 cm▪ V = 20 × 3▪ V = 60 cm³

1. Fill a beaker or graduated cylinder with water and note the volume

2. Then, place the object in the beaker or graduated cylinder

3. Note the new reading and find the difference between the two volumes

23 – 20 = 3 cm³

20 mL

23 mLvolume of the rock

Liquids have a definite volume, but they take the shape of their containers

These two glasses of orange juice look different but they contain the same volume of juice!

Gases spread out to fill their containers

The volume of gas is the same as the size of its container

Density: the measurement of how heavy something is for its size

Density = Mass ÷ Volume D = 180 g ÷ 60 cm³ D = 3 g/ cm³

Volume = 60 cm³

Mass = 180 g

Atoms: the smallest parts that make up matter Protons: exist in the center, or nucleus, of an atom

▪ Have a positive charge▪ The number of protons identifies the atom (atomic number)

Neutrons: exist in the center, or nucleus, of an atom ▪ Have no charge (neutral)

Electrons: move around the nucleus of an atom▪ Have a negative charge

Everything is made up of atoms!