Parcticle Model of Matter Yr 9 Flashcards
Solid
-particles are held next to each other in fixed positions
-only movement is vibration
-least energetic states of the matter
Liquid
-particles move about at random & are in contact with each other
-more energetic than particles in a solid
Gas
-particles move about randomly and are far apart
>means gases are much less dense than solids/liquids
-most energetic states of matter
Density
the quantity of mass per unit volume of a substance
mass/volume=density
How do you measure density on a regular object?
-calculate the length, width and height of an object and multiply these values together (volume)
-weigh the object (mass)
-do mass divided by volume to get density
What density means an object floats in water?
-the density of the object is less than the density of water (1g/cm³)
-if the density is the same as water it stays suspended in the water
-if the density is more than the density of water, it sinks
How do you measure the density of a weirdly-shaped object?
-measure the mass
-place a displacement can above on a brick
-fill the can with water and wait for the water from the spout to stop dripping
-put an accurate measuring cylinder under the can
-tie the object to a thin string and lower it into the can
-the ml of water that drips into the cylinder is the cm³ of volume
-do the mass/volume
VERNIER CALLIPER
How do you measure the density of an object with a really thin thickness?
-unlock the lock screw to open jaws
-close the jaws around the object you want to measure
-tighten lock screw
-read the scale
-add readings to get the thickness
MICROMETER SCREW GAUGE:
How do you measure the thickness of an object with a really thin thickness?
-open micrometer by turning ratchet
-place object between anvil and spindle
-close the spindle by turning ratchet
-read the scale
Internal energy
-energy stored by the particles of a substance
-energy in kinetic energy store+energy potential energy store
How do you increase the internal energy?
You do this by heating something up
Conduction
-substance is heated and its particles gain more energy
-causes them to vibrate and collide more with nearby particles
>transferring some of their energy onto them
-this passes the energy from the hot end to the colder end
Why does energy transfer to the food quicker if the pan is made of a good conductor?
-good conductor, such as metal has delocalised electrons which are able to move around and transfer energy quicker
-frying pan handles are made from good insulators to stop us from burning our hands
How is energy transferred by conduction through a solid?
-heat energy from the thermal energy store of a hot solid transfers to the thermal energy store of a cold solid object
-relies on the particles touching eachother
Why are gases bad conductors?
-move randomly which makes heat transfer less efficient
-no delocalised sea of electrons
-particles do not touch as often as solids or liquids, as they are far apart
