4.3 Particle model of matter

Question 1

What is the particle model of matter?

Answer 1

The particle model of matter explains the structure and behavior of different states of matter (solid, liquid, and gas) in terms of particles that are in constant motion.

Question 2

How are particles arranged in a solid?

Answer 2

In a solid particles are tightly packed and arranged in a regular pattern. They vibrate but do not move from their fixed positions.

Question 3

How are particles arranged in a liquid?

Answer 3

In a liquid particles are close together but not in a regular pattern. They can move around each other

Question 4

How are particles arranged in a gas?

Answer 4

In a gas particles are far apart and move freely in all directions.

Question 5

What is the difference between the behavior of particles in a solid, liquid, and gas?

Answer 5

In solids, particles vibrate in place; in liquids, particles move around each other; in gases, particles move freely and quickly in all directions.

Question 6

What happens to the movement of particles when a substance is heated?

Answer 6

When heated, particles gain energy and move faster, causing the substance to expand or change state.

Question 7

What is meant by the term “temperature”?

Answer 7

Temperature is a measure of the average kinetic energy of the particles in a substance.

Question 8

What is the relationship between temperature and particle movement?

Answer 8

As temperature increases particles move faster because they have more kinetic energy.

Question 9

What is internal energy?

Answer 9

Internal energy is the total energy stored in the particles of a substance including both kinetic and potential energy.

Question 10

What is the effect of heating a substance on its internal energy?

Answer 10

Heating a substance increases its internal energy either increasing the kinetic energy of the particles (raising temperature) or increasing the potential energy of the particles (causing a state change).

Question 11

What happens to the particles when a substance melts?

Answer 11

When a substance melts the particles gain enough energy to overcome the forces holding them in a solid arrangement, allowing them to move more freely as a liquid.

Question 12

What happens to the particles when a substance freezes?

Answer 12

When a substance freezes, the particles lose energy, slowing down and forming a more ordered structure as a solid.

Question 13

What happens to the particles when a substance evaporates?

Answer 13

When a substance evaporates particles at the surface gain enough energy to break free from the liquid and become a gas.

Question 14

What happens to the particles when a substance condenses?

Answer 14

When a substance condenses gas particles lose energy, slow down, and form liquid droplets.

Question 15

What is the specific latent heat of fusion?

Answer 15

The specific latent heat of fusion is the amount of energy required to change the state of 1 kg of a substance from solid to liquid (or vice versa) without changing its temperature.

Question 16

What is the specific latent heat of vaporization?

Answer 16

The specific latent heat of vaporization is the amount of energy required to change the state of 1 kg of a substance from liquid to gas (or vice versa) without changing its temperature.

Question 17

What is the formula for calculating the energy required to change the state of a substance?

Answer 17

Energy = mass × specific latent heat (E = m × L).

Question 18

What is meant by “pressure” in the context of gases?

Answer 18

Pressure is the force exerted by gas particles when they collide with the walls of their container.

Question 19

What is the relationship between pressure and volume in a gas?

Answer 19

The pressure of a gas is inversely proportional to its volume provided the temperature is constant (Boyle’s Law: P ∝ 1/V).

Question 20

What is the relationship between pressure and temperature in a gas?

Answer 20

The pressure of a gas is directly proportional to its temperature provided the volume is constant (Gay-Lussac’s Law: P ∝ T).

Question 21

What is the absolute zero temperature?

Answer 21

Absolute zero is the lowest possible temperature where the particles have minimum kinetic energy and theoretically stop moving. It is 0 Kelvin (-273.15°C).

Question 22

What is the Kelvin scale of temperature?

Answer 22

The Kelvin scale is a temperature scale where 0 K is absolute zero and the temperature is proportional to the average kinetic energy of the particles.

Question 23

How is energy transferred between particles?

Answer 23

Energy is transferred between particles through collisions with the particles transferring kinetic energy to one another.

Question 24

What is the definition of density?

Answer 24

Density is the mass per unit volume of a substance (density = mass/volume).

Question 25

What is the unit of density?

Answer 25

The unit of density is kilograms per cubic meter (kg/m³).

Question 26

How does the density of a substance change when it changes state?

Answer 26

When a substance changes state its density usually changes. For example, a substance generally becomes less dense when it changes from solid to liquid, and from liquid to gas.

Question 27

How does temperature affect the density of a substance?

Answer 27

As temperature increases most substances expand and become less dense.

Question 28

What is the principle of mass conservation during a state change?

Answer 28

Mass is conserved during a state change meaning the mass of the substance remains the same before and after the change.

Question 29

What is a "gas" in terms of the particle model?

Answer 29

A gas is a state of matter where the particles are far apart, move rapidly, and have high kinetic energy.

Question 30

How does the kinetic energy of particles in a gas affect its pressure?

Answer 30

The higher the kinetic energy of gas particles the greater the pressure they exert on the container walls.

Question 31

What is Boyle’s Law?

Answer 31

Boyle's Law states that for a given amount of gas at constant temperature the pressure of the gas is inversely proportional to its volume (P ∝ 1/V).

Question 32

What is Charles’ Law?

Answer 32

Charles’ Law states that for a given amount of gas at constant pressure the volume of the gas is directly proportional to its temperature (V ∝ T).

Question 33

What is the combined gas law?

Answer 33

The combined gas law combines Boyle's Law, Charles’ Law, and Gay-Lussac’s Law, and describes the relationship between pressure, volume, and temperature for a fixed amount of gas (P × V / T = constant).

Question 34

What is the ideal gas law?

Answer 34

The ideal gas law is an equation of state for a gas, given by PV = nRT, where P is pressure, V is volume, n is the amount of gas (in moles), R is the gas constant, and T is the temperature in Kelvin.

Question 35

What is the gas constant (R) in the ideal gas law?

Answer 35

The gas constant (R) is 8.31 J/(mol·K).

Question 36

What is the significance of absolute zero?

Answer 36

Absolute zero is the temperature at which the particles of a substance have the least possible amount of kinetic energy, and theoretically, the gas would have zero pressure.