particles and the periodic table Flashcards
what are the three states of matter
solid, liquid, gas
can a liquid be compressed
no
can a gas be compressed
yes
what is condensation
when gas changes into a liquid
what is freezing
a liquid turning to a solid
what is melting
a solid turning into a liquid
what is evaporation
a liquid turning into a gas
what is the melting point of a substance
the temperature at which a substance changes from a solid to a liquid
what is the boiling point of a substance
the temp at which a substance changes from a liquid to a gas
what is diffusion
the movement of particles from an area of higher concentration to an area of lower concentration
what is the difference between a compound and a mixture
compound - 2 or more elements chemically bonded together (e.g. CO2, H2O)
mixture - 2 or more elements or compounds mixed together but not chemically bonded (e.g. air, sea water)
what needs to be done to a substance for it to change state
heat energy needs to be transferred to it or removed from it
explain how heating a liquid causes it to change into gas (evaporate)
transferring heat energy to the particles, making them move faster so they move further apart. the liquid changes into a gas
explain how cooling a liquid causes it to change into a solid (freezing)
removing heat energy from the particles, making them move around less making them end up closer together. the liquid changes into a solid
does every substance have the same melting and boiling point
false
what are the melting and boiling points of water
melting = 0 degrees C
boiling = 100 degrees C
what states of matter do diffusion occur in
liquid and gas, not solids
when does diffusion stop
when the particles are spread out evenly
what is expansion
expansion of a substance occurs when it is heated. its particles spread out , making the substance take up more volume
what is contraction
contraction of a substance occurs when it is cooled. Its particles move closer together making the substance take up less volume
what is an element
substance containing only one type of atom e.g. carbon (C) , oxygen (O2)
what do elements in the same group have in common
they have similar properties
