5.1 chemistry

Question 1

properties of elements

what is it made of?
how is it made?
what is the ratio of its constituent?
What are its properties like?
Melting and boiling points

Answer 1

only 1 element
mostly naturally occuring
-
-
fixed

Question 2

properties of compounds

what is it made of?
how is it made?
what is the ratio of its constituent?
What are its properties like?
Melting and boiling points

Answer 2

2 or more elements that are chemically combined
from a chemical reaction
fixed ratio
diff properties from its constituent elements
fixed

Question 3

properties of mixtures

what is it made of?
how is it made?
what is the ratio of its constituent?
What are its properties like?
Melting and boiling point

Answer 3

2 or more elements/co pounds NOT chemically combined
usually from physical mixing
similar properties to its constituent SUBSTANCES
over a range

Question 4

ELEMENTS CAN APPEAR AS:

Answer 4

• ATOMS (not chemically bonded)
• molecules (covalenetly bonded)
• a lattice of positive ions with a sea of delocalised electons

Question 5

seperation of compounds

Answer 5

chemical means
thermal decomposition - extreme heat
electrolysis - passing electric current through compound

Question 6

seperation of mixtures

Answer 6

physical means
filtration, chromatography, etc.
little/no energy changed involved in separartion

mictures like alloys are note easily seperated and require large amounts of energy