Chapter 1The Properties of Matter

WHAT IS MATTER?

• Everything Is Made of Matter– matter = anything that has volume and mass

• Matter Has Volume– volume = amount of space taken up

(occupied) by an object– Things with volume cannot share the same

space at the same time

– Liquid volume– Measuring the volume of liquids• Instrument? Graduated cylinder

• Curve @ liquid’s surface? meniscus

• Will a liquid in any container have a meniscus? Yes! In larger containers, the meniscus is too flat to see.

• Units? Milliliters (mL) or Liters (L)

– Solid volume• Units : cubic units – m3 or cm3

• How do we get these units? Use three dimensions to calculate volume – length x width x height

– Comparing solid & liquid volume• Equal units? 1 mL = 1 cm3

–Can express vol of liquid in cubic units; however, vol of solids are never expressed in L or mL

– Measuring the volume of gases• Possible? Yes… how?• Gas expands to fill its container–So if you know the volume of the

container then you know the volume of the gas.

• Matter Has Mass– mass = amount of matter that something is

made of• ex: Earth vs. peanut vs. speck of dust

– Is a puppy like a bowling ball?• An object’s mass can be changed only by

changing amt. of matter in object– Consider… constant? growing?

• The Difference Between Mass & Weight– Weight is different from mass.– Understanding the difference…• gravity = force of attraction between objects that

is due to their masses• G. causes objects to exert pull on other objects• Does all matter experience gravity? Yes! why or

why not? b/c all matter has mass.• Amount of attraction depends on: 1) masses of

the objects and 2) distance between them

– May the force be with you• When is gravitational force experienced? By all

objects in the universe, all the time.

• Gravitational force experienced by objects with small masses is very slight.

• Earth’s large mass & gravitational force is great when in conjunction with other large objects, like our atmosphere, the space shuttle, & planets

– So what about weight?• weight = measure of the gravitational force exerted on an

object

• obj & Earth have mass obj & Earth are attracted to each other force exerted on obj b/c of attraction to Earth weight of obj is measure of gravitational force

– At a distance• Attraction btwn obj decreases as distance btwn increases

– Therefore gravitational force decreases, also

• Mass doesn’t change, but weight does

– Massive confusion• Most obj’s weigh same anywhere on Earth b/c

gravitational force is about same everywhere on earth. That’s why mass and weight are used interchangeably…

• Weight depends on mass but they aren’t the same!

• Measuring Mass & Weight

–Weight is a measure of gravitational force, and must have units of force.

• basic SI unit : N_,_Newton_

–N approximately equal to 100 g mass

–on Earth N = 100 g

– Figure 8

• Mass Is a Measure of Inertia– inertia = the tendency of all objs to resist any change

in motion.

• B/c of inertia an object at rest will remain at rest until something causes it to move and obj in motion will move at same rate, in same direction until something acts to change its rate(speed) / direction

– Why is mass a measure of inertia? ____________________________________________________________________________________• B/c obj with large mass is harder to start in motion &

harder to stop than obj with smaller mass.– ex:_____________________________________________________

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