(what's the) Matter and materials Flashcards
what is matter?
anything that takes up space and has a mass
what is an element?
a pure substance that cannot be split into simpler substances
what are atoms?
the smallest part of a chemical element
what is the periodic table of elements?
a list of elements according to their atomic number
what is made up of matter?
everything we can see and touch including air
what is matter made up of?
atoms
what are elements?
made up of atoms of the same kind
listed on periodic table of elements
divided into metals, non metals, semi metals
periods and groups
what are sub atomic particles?
atoms are made up of samller particles called:
- protons
- electrons
- nuetrons
draw diagram of an atom:
what is the central region of an atom?
nucleus
why are atoms neutral?
because number of protons=nuetrons
what are the properties of a pure substance?
phase
conductivity
solubility
density
magnetism
melting point
boiling point
what are molecules?
two or more atoms chemicals bonded to form a unit
what are compounds?
different elements reacted chemically to form molecules of compounds
what is the ratio of atoms in compounds?
atoms in a compound are combined in a fixed ratio
water = 2 : 1 (two hydrogen atoms and one oxygen atom)
how are the atoms in molecules held together?
by a chemical bond
what is a chemical bond?
strong forces of attraction that holds atoms together
how are compounds formed?
by means of chemical reactions
what does decomposing a compound mean?
when compound is broken down into its composite elements
how can substances be decomposed?
*triangle*
heating. example: mecury oxide ———————> mercury + oxygen
electrolysis, decomposing using electrical energy
what is a mixture?
a combination of two or more substances that have not yet reacted chemically and can be seperated by physical processes
name the methods of seperating mixtures
hand sorting
magnetic seperation
filtration
seperation funnel (remember:(seperation fun))
distillation:
- evaporation
- fractional distillation
chromatography
name the conditions for substances to be hand sorted
both substances must be solids and big enough to pick up with your hands
example: peanuts and raisens
name the conditions for substances to be magneticly seperated
one substance must be magnetic and the other non magnetic
example: iron filings and sulphur powder
name the conditions for substances to be filtrated
one substance must be a liquid and the other a solid which is insoluble in a liquid
example: sand in water
name the conditions for substances to be seperated with a funnel (or funnily seperated)
substances with different desities can be seperated with a funnel
name the conditions for substances to be seperated by (distillation) evaporated
a slid dissolved in a liquid
example: sugar and water
name the conditions for substances to be seperated by fractional distillation
substances (liquids) with different boiling points
example: alcohol and water
what is chromatography?
rate at which different dissolved substances move in a solute
example: filter paper and ink
what are the states of matter?
solids, liquids, gases
name the properties of a solid
- particles packed closeley together
- small spaces between particles
- strong forces of attraction between particles
- particles do not move freely ( vibrate )
- fixed shape
name the properties of a liquid
- particles are close together but looseley packed
- particles can move around quickly
- weaker forces of attraction between particles than in a solid
- small spaces between particles
name the properties of a gas
- particles are wideley spread no fixed shape
- moves fast and freely
- weak forces of attraction between particles
- large spaces between particles
what is diffusion?
the movement of particles in a liquid or gas from an area of high concentration from an area of low concentration until evenly distributed
how is diffusion a result of kinetic energy?
gas particles move faster than liquid particles therefore there is more kinetic energy
diffusion is faster in a gas than a liquid
what is change of state?
when a matter changes into another state or form
heating or cooling can cause change of state
what happens when matter is heated?
particles gain more kinetic energy
- particles vibrate more
- particles knock against each other, particles start to expand
- eventually particles begin to break away from their position and can move past each other
- at low temperature parts of a liquid move slowly
- liquid heated, more kinetic energy, expands = a gas
- liquid is therefore evaporating
what happens when matter is cooled?
when particles cool —-> less kinetic energy
particles move closer together
what is density?
amount of mass per unit for that material
density =
<span>mass(g)</span>
———————
volume
what can density tell us?
how closeley packed the particles are in a material
what has a higher density than the same material in liquid or gas form?
solids
- exception: water
- ice cubes float on water
- water expands when frozen
is solid water less dense than liquid water at the same temperature?
yes
what does density of materials depend on?
particles
state of matter:
example: mass of particles
size of spaces between particles
kinds of particles
would a material with a low density float on a liquid with a high density?
yes
what is expansion?
- to grow in size or become larger
- happens when materials gain energy
- partcles move faster
- forces between particles weakens
- particles move further apart
what is contraction?
- to become smaller or shrink
- materials lose energy (cool down)
- particles move slower
- forces between particles become sronger
- particles move closer together
explain how can expansion and contraction be dangorous
in cold countries pipes can freeze, water in pipes expand when frozen, pipes can therefore burst
what is pressure?
- gas particles in a container move around very quickly
- they bump into each other and collide with container
- when gas particles hit wall of container = apply force
- this is called gas pressure
- the more particles collide with the walls, the greater the pressure
