Solids, Liquids, Gases, Magnetism

Question 1

Pressure at a point in a gas or liquid which is at rest…

Answer 1

Acts equally in all directions.

Question 2

How do particles move in a gas?

Answer 2

Collide with each other and walls, changing speed and direction, random motion.

Question 3

What does the collapsing can demo show?

Answer 3

Air is pushing out the same on from inside the can as from the outside of the can.

When air sucked out, more air is pushing in so implodes.

Question 4

What causes pressure in atmosphere

Answer 4

Weight of the air particles in the atmosphere above is acting on our area, exerting a pressure

pressure increases closer to the ground. More air particles pushing down at the bottom

Question 5

What happens when solid melts to form a liquid:

Answer 5

Particles gain kinetic energy when heated and vibrate faster, overcome forces of attraction that hold them together and the regular pattern breaks down. Particles can now slide past each other (still close together)

Question 6

What happens when a liquid evaporates/boils to form a gas?

Answer 6

The particles gain kinetic energy when heated and move further apart. Forces of attraction completely break (overcome attraction)

Big bubbles of gas form in the liquid - boiling

Question 7

Describe the arrangement and motion of particles in solids:

Answer 7

Particles close together, touching
Fixed, regular arrangement, vibrating about fixed positions(Particles don’t have much energy)
Strong forces of attraction hold particles

Question 8

Describe the arrangement and motion of particles in a liquid:

Answer 8

Weaker forces of attraction between particles.
Particles close together, sliding past each other
Arranged irregularly, more energy than those in solids.
Random directions, low speeds

Question 9

Describe the arrangement and motion of particles in a gas

Answer 9

Irregularly arranged
Move freely, constantly colliding w each other, random directions, speeds
Almost no forces of attraction between particles
Particles have more energy than in liquids, solids

Question 10

What’s the relationship between kelvin temp of a gas and the average kinetic energy of its molecules?

Answer 10

Temperature of a gas in kelvins is proportional to the average kinetic energy of its particles

Question 11

What does an increase of temperature result in?

Answer 11

An increase in the average speed of gas molecules?

Question 12

How does Brownian motion support particle theory?

Answer 12

Robert Brown 1827 noticed pollen grains moved with a random zig zag motion.

Any particle movement = Brownian motion (supports particle theory of different states of matter)

Large heavy particles (eg smoke) can be moved with Brownian motion by smaller lighter particles (eg air) travelling at high speeds - this is why smoke particles in air appear to move around randomly when observed in a lab

Question 13

What’s particle theory?

Answer 13

Says that gases consist of v small particles which are constantly moving in completely random directions.
Hardly take up any space - most of a gas is empty space.

(They collide with each other and the walls. Increase temp = more particle energy)

Question 14

How do molecules exert a force, pressure on walls of their container?

Answer 14

Molecules in a gas have a random motion in different speeds and directions, colliding with each other and the walls of the container, exerting a force over their area, this is pressure.

Question 15

What’s absolute zero and why is it a thing?

Answer 15

The coldest anything can get is -273 degrees C. (Absolute zero!) atoms have as little kinetic energy as possible. No kinetic energy left to be extracted from the gas.

Absolute zero is the start of Kelvin scale.

Question 16

How to convert from Kelvin to Celsius and the other way around?

Answer 16

Add 273 to Celsius to get kelvin.

Subtract 273 from kelvin to get Celsius.

Question 17

What’s the relationship between pressure and Kelvin temp of a gas in a sealed container?

Answer 17

Kelvin temperature and pressure are directly proportional

Heat a gas- move faster w more kinetic energy - hit walls harder - more pressure

Question 18

What’s Boyle’s Law?

Answer 18

For a fixed mass of gas at a constant temperature, pressure is inversely proportional to volume

p1V1 = p2V2

pressure x volume = constant

Straight line through origin when P y axis 1/V x axis

Question 19

What’s Pressure Law?

Answer 19

For a fixed mass of gas at a constant volume, temperature (K) is directly proportional to pressure.

p1/T1 = p2/T2

pressure/temperature (K) = constant

Straight line through origin when placing P y axis and T x axis

Question 20

Magnets repel and attract…magnets attract…

Answer 20

Magnets repel and attract other magnets and attract magnetic substances

Question 21

What’s a magnetic field line?

Answer 21

Display the regions where the magnetic material experience a force. Represent the shape and direction of magnetic fields.

Question 22

Describe the properties of magnetically hard and soft materials:

Answer 22

A magnetically hard material retains its magnetic properties for a long period of time/ permanently. They are hard to magnetise and demagnetise. (Steel)

A magnetically soft material loses its magnetic properties almost as soon as it leaves a magnetic field. Easy to magnetise and demagnetise. (Iron)

Question 23

How is magnetism induced in some materials?

Answer 23

In some materials (magnetic), when placed in a magnetic field, acts as a magnet. (Magnetism has been induced by original magnet)

The closer the magnet and magnetic material, the stronger the induced magnetism.

Question 24

Describe an experiment to investigate the magnetic field pattern for a permanent bar magnet and that between two bar magnets:

Answer 24

• put magnet(s) underneath paper, scatter iron filings on top. gently tap paper.
• multiple compasses to see the lines coming out of a bar magnet/ between two bar magnets. / or use one compass and move it around, tracing its position on paper before moving

(Compasses and iron filings align themselves w magnetic fields)

Question 25

Describe how to use two permanent magnets to produce a uniform magnetic field pattern;

Answer 25

Like poles repel, opposite poles attract

Place the north and south poles of two permanent magnetic fields close together (and they attract) to create a uniform field between the two magnets.

Question 26

Density of an irregular object:

Answer 26

Displacement method! (Only works for objects denser than water-sink)

Put known volume of water in a cylinder. Put in object. The amount the volume of water has increased is the volume of the object.

Mass / volume