Particles Flashcards
Describe the particles in solids, liquids and gases in terms of their arrangement, movement, forces and energy
Solids- solids are held in a fixed shape and volume, the particles are held tightly together in a regular pattern which can only vibrate on the spot with strong inter-molecular forces between them. Solids have the least amount of energy than the other states of matter.
Liquids- liquids aren’t held in a fixed shape but have a fixed volume. The particles are held together however not as tightly as solids in a random arrangement with the ability to move around randomly over each particle and change places. They also have fairly strong inter-molecular forces and more kinetic energy than solids but less than gases.
Gases- gases aren’t held in a fixed shape and don’t have a fixed volume. They are arranged randomly and the particles move freely apart very fast in all directions. They also have weak inter-molecular forces and a lot of energy.
Calculate the density of a substance
Density(kg/m³)= mass(kg)/volume(m³)
Example:
A rock with a volume of 15cm³ and a mass of 45 g. What is the density? 45g= 0.045kg
15cm³= 0.15m³
0.045/0.15=0.3kg/m³
Describe how to find the density of regular and irregular objects and liquids by experiment
To find the density of a regular object you have to firstly find the mass then measure the sides of the object to find the volume. Finally divide the mass and the volume together to find the density. To find the density of an irregular object, you have find the mass then use a eureka can to find the volume. Divide the mass and volume together to find the density.
Describe how increasing the temperature of a substance affects its internal energy
When the temperature increases the internal energy increases as well this is because the increase in temperature will give the particles more energy so they will move around more, causing the kinetic energy to increase which in turn increases the internal energy.
Describe what is meant by specific latent heat
The specific latent heat of a substance is the amount of energy that is needed to change 1kg of it from one state to another.
Interpret heating and cooling curves
Heating curves show how the temperature changes as a substance is heated up. Cooling curves are the opposite. They show how the temperature changes as a substance is cooled down. Just like heating curves, cooling curves have horizontal flat parts where the state changes from gas to liquid, or from liquid to solid
Use the specific latent heat equation to calculate the energy required to change the state of a substance
Energy(J)= Mass(kg)Specific latent heat(J/kg)
Example: The 0.05kg wax has a specific latent heat of 80000J/Kg. Calculate the energy.
0.0580000=4000J
Describe how to find the specific heat capacity of a substance by experiment
Energy(J)= Mass(kg)Specific heat capacity(J/kg°C)temperature rise(°C)
First find out the mass of the substance, then find out the change in temperature when a certain amount of energy was supplied to it. Next, multiply the mass and change in temperature and finally divide the answer by the energy.
Describe evidence that gas particles move in a random motion
Brownian motion shows the gas particles moving in a random motion in all directions because of the random impacts of the gas particles colliding with one another .
Describe why a gas exerts of a force on a surface
The gas particles collide with the surface bouncing off it exerting a force which creates a high pressure.
Describe how the pressure of a gas in a sealed container is affected by the temperature
If the temperature of the container increases, the energy will be transferred to the gas particles which will increase the kinetic energy and cause them to collide with the surface and with one another more often and faster. The particles want to spread out more but can’t because of the sealed container and fixed volume. This collision will exert a greater force on the container surface which will increase the pressure.
(Triple Science) Describe the relationship between the volume of a gas and the pressure of the gas
Pressure and volume are inversely proportional so if the pressure of a gas increases and doubles, the volume will decrease and halve.
(Triple Science) Use Boyle’s Law Equation
Pressure(Pa)*Volume(m³)=constant
As the volume decreases the pressure will increase because the particles will collide with the container more often and less volume means less space for the particles so they will collide more as there is less space to move.
(Triple Science) Explain how increasing the pressure on a gas can affect the temperature of the gas
As the pressure increases on a gas, the temperature also increases. This is because if the pressure has increased this means that greater force is being exerted on the container meaning that the particles have gained more energy and are colliding with the container and themselves more faster and often which can happen only if the temperature has increased to give them the energy to do so.
Describe what is meant by specific heat capacity
Specific heat capacity of a substance is the amount of energy that is needed to change the temperature of 1kg of it by 1°C.
