Chapter 08 : Kinetic Particle Model of Matter

Question 1

8.1

kinetic particle model of matter

Answer 1

the kinetic particle model of matter is made up of tiny particles that are in continuous motion

Question 2

8.1

properties of solids

Answer 2

at particle level
* arrangement : closely packed and arranged regularly, less energy
* motion : particles vibrate about fixed positions - held by strong attractive forces between the particles

• solids have highest density
• fixed volume
• fixed shape

densest

Question 3

8.1

properties of liquids

Answer 3

at a particle level
* arrangement : less closely packed and arranged irregularly
* motion : the particles slide over e/o throughout the liquid w/o fixed positions. forces holding paticles together weaker than solid
* lower density than solids [ denser than air ]
* fixed volume
* fixed shape

denser than air
less dense compared to solids

Question 4

8.1

properties of gases

Answer 4

at a particle level
arrangement : far apart from one another in a irregular pattern, most energy
motion : move freely in any direction, weak forces between the particle are weak
* least dense
* no fixed volume
* no definite shape [ compressible ]

least dense

Question 5

define brownian motion

Answer 5

random erratic movements of particles suspended in a liquid or gas caused by constant collisions

Question 6

8.2

temperature

Answer 6

temperature rises with the average kinetic energy of particles in a body (vice versa )

temperature reading is an idication of the kinetic energy of the particles of the substance

Question 7

8.2

pressure

Answer 7

gases exert pressure, which is the average force exerted by the particles per unit area

when a gas particle colides with the inner walls of the container, it exerts a force F on the wall
when many gas particles colides with the inner walls of the container, the forces add up. total force exerted by gas per unti area : pressure

Question 8

qns

how does increase in temperature affect the average kinetic energy of the particles in matter

Answer 8

when temperature increase, the average kinetic energy of the particles in the body increases

when temperatture increase, there is more energy in the particles. the increase in energy results in the particles moving about and colliding to e/o at a faster rate, therfore the average kinetic energy increase.

Question 9

how does a thermometer measure the temperature of a substance

Answer 9

when a substance [water] is heated, the kinetic energy of particles vibrate/move faster
hence, when the thermometer comes in contact with water, the water particles high in kinetic energy transfer some of the energy to the less energetic particles in the thermometer to collisions
with more energy, the particles tend to pish e/o further apart so the matter expands. however, liquids expand more easily than solids. the liquid column in the thermometer expands along the calibrated scale, thus measuring the temperature