Particle Model Flashcards
(24 cards)
What does the kinetic theory describe?
It explains the states of matter in terms of particle motion and arrangement.
What is the formula for density?
Density = mass ÷ volume (ρ = m / V).
What happens to mass during changes of state?
Mass is conserved — it does not change.
What distinguishes physical from chemical changes?
Physical changes are reversible and don’t alter substance properties.
What happens to energy when a system is heated?
It increases internal energy, raising temperature or causing a change of state.
What is specific heat capacity?
The energy needed to raise 1 kg of a substance by 1°C.
What is the formula for change in thermal energy?
ΔQ = mass × specific heat capacity × Δtemperature (ΔQ = m × c × Δθ).
What is specific latent heat?
The energy needed to change the state of 1 kg of a substance without changing temperature.
What is the formula for thermal energy during state change?
Q = mass × specific latent heat (Q = m × L).
How can unwanted energy transfer be reduced?
By using thermal insulation like foam or double glazing.
What is absolute zero?
The temperature at which particle motion stops, −273°C or 0 K.
How do you convert between Celsius and Kelvin?
Add 273 to Celsius to get Kelvin; subtract 273 to get Celsius.
What causes gas pressure?
Particles colliding with container walls.
What happens to particle velocity as temperature increases?
Particles move faster, increasing pressure if volume is constant.
What happens when the volume of a gas decreases?
Particles collide more frequently, increasing pressure.
What is the relationship between pressure and volume in gases?
P₁V₁ = P₂V₂ for a fixed mass at constant temperature.
What does doing work on a gas do?
It increases the internal energy and can raise temperature.
What is the pressure in a fluid due to?
The weight of the fluid above and atmospheric pressure.
How does fluid pressure act?
Normal (at right angles) to any surface in contact with the fluid.
How does fluid pressure vary with depth?
It increases with depth and density.
What is the formula for pressure in liquids?
P = h × ρ × g.
What causes upthrust in a fluid?
The difference in pressure above and below the object.
What determines if an object floats?
If upthrust equals or exceeds the object’s weight.
What is upthrust equal to?
The weight of the displaced fluid.
