Solids, Liquids and Gases Flashcards
What is the density of a material?
-mass per unit of volume
Equation for density hen you know the mass and volume
Mass/density x volume
What is pressure?
Amount of force applied per unit of area
State an equation linking pressure, force and area
force /pressure x area
Unit of pressure and how else can it be expressed?
Pascals
1Pa= 1 Newton / meter²
In solids, pressure acts in the direction of force. In which direction does pressure act in liquids or gases?
It acts in all directions equally
State and equation linking pressure difference, depth, density of liquid and gravitational field strength
pressure (Pa) =depth (m) x density (kg/m³) x g (m/s²)
p=h x p x g
How do you convert between degree celsius and kelvin?
Cº → +273→ Kelvin
Explain why Kelvin scale is used in science instead of celsius
Kelvin scale is directly proportional to the average kinetic energy of the particles. At 0K particles do not move but at 0ºC particles still move.
Explain the pressure of a gas in terms of the motion of particles
The particles move in random directions. WHen they collide with the walls of a container they exert a force which acts at a right angle to the container. This causes pressure.
How does changing the temperature of a gas affect the velocity of the particles?
The higher the temperature, the more kinetic energy the particles have and therefore the faster the average velocity of the particles
How does the temperature affect the pressure of a gas?
Increasing temperature, increases the average kinetic energy of particles so they move faster,
Therefore particles collide harder and more frequently. This increases the pressure
State an equation linking initial pressure, final pressure, initial temperature and final temperature
P1/T1=P2/T2
Explain how changing the volume of a gas affects the pressure of the gas
Volume and pressure are inversely proportional assuming temperature and mass of the gas is kept constant. Therefore as the volume decreases (gas in compressed) pressure increases; as a volume increases (gas is expanded) pressure decreases
State an equation linking initial pressure initial volume, final pressure and final volume for a gas
P1 X V1 = P2 X V2
State 2 assumptions you should make while using this equation
-Fixed mass
-Fixed temperature
In a bicycle pump, how does pressing the piston lead to an increase in the temperature inside the piston?
-Pressing the piston leads to a decrease in volume
-This leads to an increase in pressure
-The particles collide more frequently
-The velocity of the particles increases
-Therefore their temperature will increase
What is meant by a state of matter?
A form in which matter can exist, based on the particle arrangement in a substance
Order the states on matter starting with the one where the particles have the least kinetic energy
Solid→Liquid→Gas
Use kinetic energy to explain the structure of liquids
The particles have some kinetic energy. They are free to move and can move around in random directions within the volume of the liquid
Explain the movement of particles in a solid
The particles vibrate around a fixed position as they do not have enough kinetic energy to move freely
Explain the structure of particles in gases
Almost no forces between them and therefore they are completely free to move and move at high speeds in random directions
Which state is the densest and why?
Solids, because the particles are tightly packed together in a uniform structure
Does a gas have a high or low density and why?
A low density, because there is no attraction between the particles meaning that they are very spread out. This means there are less particles per unit volume.
Why is a liquid described to have a moderate density but still similar to that of a solid?
The particles are still tightly packed together but they can slide over eachother
Name physical changes that can occur which don’t change the mass of a substance
-Melting
-Freezing
-Boiling
-Evaporating
-Condensing
Why does heating increase the temperature of a substance?
Temp of a substance depends on the average kinetic energy of the particles. When you jeat the substance, you put in thermal energy therefore kinetic energy of the particles increases therefore they move faster and temp increases.
How does heating cause a substance to change state?
At specific temps, when you heat the substance thermal energy supplied is used to break the bonds of attraction between particles causing a state change. During state change temperature does not change since average KE does not increase
What is specific heat capacity?
The energy require to raise one kilogram of a material by one degree celsius
Equation to calculate the energy required to change the temperature of a substance?
Q = m x c x ΔT
