Solids Liquids and Gases Flashcards
What is the definition of density?
Density is the mass per unit volume, measured in kilograms per metre cubed (kg/m³)
Density formula: density = mass/volume
How do you find the density of a liquid?
- Measure the mass of the empty measuring cylinder
- Fill it with the liquid and measure the new mass
- Calculate the mass of the liquid by finding the difference
- Read the volume from the cylinder
- Use the equation to find density
Ensure to read the volume straight-on to avoid parallax error
What is the formula to calculate density?
density = mass/volume
This equation applies to both liquids and solids
How do you find the density of a solid?
- Measure the mass of the solid
- If regularly shaped, measure dimensions and calculate volume
- If irregularly shaped, immerse it in water and measure displaced volume
- Use the equation to find density
Regular solids use geometric formulas; irregular solids use the water displacement method
What is the definition of pressure?
Pressure is the force per unit area, measured in Pascals (Pa)
Pressure formula: pressure = force/area
How does lying on a bed of nails demonstrate the concept of pressure?
Lying on a bed of nails spreads the body weight over a larger area, resulting in lower pressure compared to lying on a single nail
The total area is either a single point or many points spread out
What happens to pressure at a point in a gas or liquid at rest?
The pressure acts equally in all directions and causes a force at right angles to any surface
This is due to the movement of particles colliding with surfaces
How does pressure change with depth in a fluid?
Pressure increases with depth due to the weight of particles above the point, fluid density, and gravitational field strength
Formula: p = pgh, where p = pressure, p = density, g = gravitational field strength, h = depth
Fill in the blank: The density of a liquid affects the _______ at a given depth.
pressure
Higher density means more particles per unit volume, increasing weight and pressure
What is the behavior of gas molecules?
Gas molecules move rapidly and randomly due to collisions with other gas molecules.
This behavior is a fundamental characteristic of gases.
How do gases exert pressure on a container?
Gases exert pressure on a container due to collisions between gas molecules and the wall.
Pressure is a result of molecular motion and collisions.
What happens to gas molecules when they rebound off the walls of a container?
They change direction, so their velocity and therefore momentum changes.
This change in momentum results in the exertion of force.
What is the relationship between temperature and pressure at constant volume?
At a constant volume, if the temperature increases, the pressure increases.
This is because molecules move faster and collide harder and more frequently with the walls.
What is absolute zero in degrees Celsius?
Absolute zero is -273°C.
It is the temperature at which the pressure of a gas is zero.
How is absolute zero defined on the Kelvin scale?
On the Kelvin scale, absolute zero is defined as 0 K.
One Kelvin increment is equal to one degree Celsius increment.
