materials

Question 1

solids

Answer 1

particles held together very tightly
fixed positions
don’t move so solids keep a definite shape
can’t be easily compressed because already the particles usually dense, lots of particles packed tightly

Question 2

liquids

Answer 2

particles close - but free to move past each other.
particles moving constantly in all directions
don’t keep a definite shape - think puddles
won’t compress easily
quite dense quite a lot of particles in a small volume

Question 3

gases

Answer 3

weak attraction
particles far apart move freely in all direction
move fast and collide
don’t keep a shape or volume and will expand
can be compressed early because there is fee space
low densities because not many particles

Question 4

compounds

Answer 4

compounds are formed from chemical reactions
they contain two or more elements joined up
(if they are different but not joined up it is a mixture)

Question 5

what is a chemical reaction

Answer 5

a chemical reaction involves chemicals (called reactants) combining together or splitting apart to form one or more new substances (called the products)
the new compound is always totally different from the original elements
e.g. iron and sulphur + heat = icon sulfide

Question 6

molecule

Answer 6

a molecule is when two or more atoms going together

the ‘join’ is a chemical bond

Question 7

element

Answer 7

all the atoms are the same in an element

they can be joined up or not joined up but they must be the same

Question 8

mixture

Answer 8

different elements but not joined up (think cake mixture before it is cooked - chemical reaction)
two or more different substances

Question 9

dissolving and separating

Answer 9

you know this

Question 10

what is upthrust

Answer 10

up thrust is the upward force that a liquid of gas exerts on a body floating in it it