Section 23: Matter Flashcards
What is density
Density is a measure of the compactness of a substance, it relates the mass of a substance to how much space it takes up.
Equation for density
Density= mass/volume
How to find the density of a solid and liquid
- Use a measuring cylinder
- Use a mass balance to measure the mass of the empty measuring cylinder.
- Pour any liquid you investigating measure the mass of a cylinder again – the difference in mass is equal to the mass of a liquid.
- Find the volume from the cylinder scale.
How to find the volume of a prism
Find the area of its base then multiply it by height
How to find the volume of a cube
Length X width X height
How to find the volume of an irregular shape
You can find us volume using the fact that an object emerged in water will displace a volume of water equal to in volume
How to use a density bottle
- Measure the mass of the object using a mass balance.
- Fill the bottle with a liquid of a known density.
- Place to stop her into the bottle and dry outside.
- Measure the mass of the bottle.
- Into the bottom and place the object into the density bottle, repeat steps, two and three, then measure the mass of the bottle.
- Calculate the volume of displaced water.
Calculate the density of the object using the equation of density, with a mass measured in step one, and the volume you calculated to step six
How to calculate the volume of displaced water
The mass of displaced water equals mass2 - (m3-m1)
Then use the density of the water so you can use V=m/p to find the volume displaced.
What are the particles like in a solid?
- Strong forces of attraction hold the particles close together in a fix regular arrangement.
- The particles don’t have a much energy in the kinetic energy stores, they can only vibrate about in their fixed positions.
What are the particles like in a liquid?
The force of attraction between particles are weaker.
The particles are close together but can move past each other and form an irregular arrangement.
They don’t have as much energy in the kinetic stores than the particles in a solid as they move in random directions at low speed.
What are the particles like in a gas?
There are almost no forces of attraction between particles
particles have more energy in the kinetic energy stores than those in liquids
free to move as a travel in random directions a high-speed
What is a thermal energy store?
The energy in a substances thermal energy store is held by its particles in the kinetic energy stores
What happens when a substance is boiling
When you heat a liquid The extra energy is transferred into the particles kinetic energy store, making a move faster. Eventually, enough of the particles have enough energy to overcome the attraction to each other big bubbles of gas form in the liquid.
What happens when a substance is melting
The extra energy is transferred into particles, kinetic energy store, making a move faster. The extra energy makes the particles vibrate faster until eventually the forces between are partly overcome in the particle start to move around.
What is specific heat capacity?
The amount of energy needed to raise the temperature of 1 kg of a substance by 1°C
What is thermal energy?
The total energy stored by particles making up a substance or a system
What is temperature?
The average internal energy of a substance
What is the equation of specific heat capacity?
Change in thermal energy = m X c X change in temperature