Particle model of matter full set

How do gas particles move?

Freely, randomly, and at high speeds.

What causes gas pressure?

The collisions of gas particles with the walls of a container.

How does temperature affect gas pressure?

Higher temperature increases pressure as particles move faster and collide more frequently.

What is Boyle’s Law?

For a fixed mass of gas at constant temperature, pV=constant (pressure and volume are inversely proportional).

What happens to gas pressure if volume decreases?

Pressure increases.

What does absolute zero represent?

The temperature at which particle motion theoretically stops (−273.15∘−273.15∘C or 0 K).

How is temperature measured in Kelvin?

Add 273 to the temperature in Celsius.

What is the relationship between pressure and temperature?

Pressure is directly proportional to temperature in Kelvin for a fixed volume.

Why does a balloon expand when heated?

Gas particles gain kinetic energy, increasing pressure and volume.

How can gas pressure be reduced?

By increasing the volume or reducing the temperature.

What is the kinetic theory of gases?

It explains gas behavior based on particle motion and collisions.

What happens to particle speed as temperature increases?

Particle speed increases.

How is work done on a gas?

By compressing it, which increases its internal energy.

Why does releasing gas from a high-pressure container cool it?

Expanding gas does work, losing energy and cooling.

What happens when gas particles collide with each other?

They transfer energy but do not lose it overall (elastic collisions).

What is specific latent heat?

The energy required to change the state of 1 kg of a substance without changing its temperature.

What is the formula for specific latent heat?

Q=mL, where Q is energy, m is mass, and L is specific latent heat.

What are the units of specific latent heat?

Joules per kilogram (J/kg).

What is the specific latent heat of fusion?

The energy required to change 1 kg of a substance from solid to liquid.

What is the specific latent heat of vaporization?

The energy required to change 1 kg of a substance from liquid to gas.

How does specific latent heat differ for different substances?

It depends on the substance's molecular structure and bond strength.

Why doesn’t temperature change during latent heat transfer?

The energy goes into changing the state, not increasing kinetic energy.

What factors affect the total energy required for a change of state?

The mass of the substance and the specific latent heat.

How can you experimentally determine specific latent heat?

Measure the energy supplied and the mass of the substance, then use L=Q/m

What is the role of specific latent heat in evaporation?

It explains why evaporation absorbs heat from the surroundings.

What type of latent heat is involved in freezing?

Latent heat of fusion.

What happens to the energy released when steam condenses?

It is transferred to the surroundings as latent heat of vaporization.

Why is the specific latent heat of vaporization usually higher than that of fusion?

More energy is required to separate particles completely in the gas phase.

How does high specific latent heat be

Water's high latent heat of vaporization helps regulate body temperature through sweating.

What is the specific latent heat of fusion for ice?

Approximately 334,000 J/kg

What is internal energy?

The total energy of all the particles in a substance, including kinetic and potential energy.

How is internal energy affected by heating a substance?

Heating increases the internal energy by increasing the kinetic energy of the particles.

What are the main types of energy in internal energy?

Kinetic energy (due to motion) and potential energy (due to particle interactions).

What happens to the temperature of a substance during a change of state?

The temperature remains constant.

Why doesn’t the temperature change during a change of state?

Energy is used to break or form bonds, not to increase kinetic energy.

What is a physical change?

A change in state or form that does not alter the chemical composition of a substance.

What happens to the internal energy when a substance freezes?

Internal energy decreases as particles lose potential energy.

How do particles behave in a gas compared to a solid?

Gas particles move freely and randomly, while solid particles vibrate in fixed positions.

What are the processes called when a substance changes from solid to liquid and liquid to gas?

Melting and evaporation/boiling, respectively.

What is the reverse process of condensation?

Evaporation or boiling.

What is sublimation?

The direct change of state from solid to gas without becoming a liquid.

How does pressure affect the boiling point of a liquid?

Higher pressure increases the boiling point.

What is required for a change of state to occur?

Energy transfer, either absorbed or released.

What type of change is a change of state: chemical or physical?

Physical.

How does internal energy differ from temperature?

Internal energy includes both kinetic and potential energy, while temperature only measures average kinetic energy.

What is the formula for density?

Density = mass/volume (P=m/V)

What is the SI unit of density?

Kilograms per cubic meter (kg/m³).

How do you find the volume of a regular solid?

Measure dimensions with a ruler and use a formula (e.g., Volume=length×width×height

How do you find the volume of an irregular solid?

Submerge the object in a measuring cylinder filled with water and record the displaced volume.

What equipment is used to measure mass?

A balance or scale.

Why is density a useful property of materials?

It helps identify substances and determine their applications.

What happens to density if the mass of a material increases while its volume remains constant?

Density increases.

What happens to density when a material expands?

Density decreases because the volume increases while mass remains constant.

What is the density of water?

Approximately 1000 kg/m³

What does it mean if an object floats in water?

Its density is less than 1000 kg/m³

Why are gases less dense than liquids and solids?

Gas particles are far apart, so they occupy a much larger volume.

How does temperature affect the density of a substance?

Density decreases as temperature increases because most substances expand when heated.

What is the relationship between mass and density?

Mass is directly proportional to density for a given volume.

Can two materials have the same mass but different densities?

Yes, if their volumes are different.

How do you calculate the mass of an object from its density and volume?

Mass=Density×Volume.