CHAP 12 THE REACTIVITY SERIES Flashcards
metals are malleable & ductile. what is the definition & reason of malleable & ductile ?
malleable: can be bent, shaped & made into sheets
ductile: can be stretched and drawn into wires without breaking
reason: the atoms in metals are orderly arranged in layers and the layers of atoms can slide over one another easily when a force is applied.
why are metals good conductors of electricity?
due to the presence of free moving electrons in the metallic structure ( sea of delocalised electrons )
why do metals have high boiling & melting points?
large amount of energy was needed to overcome the strong metallic bonds
which metal have the exceptions of high & low boiling point with low density?
mercury ( liquid at r.t.p )
why do most metals have high densities?
metal atoms are closely packed together in a regular arrangement.
which group of metals have low densities?
group 1
metals lose electrons , are they positively or negatively charged ions?
positive ions
what do metals and acids react and form?
salt & hydrogen gas
what are the three metals that do not react with acids?
copper
silver
gold
what oxides do metals react with oxygen form?
basic & amphoteric oxides
what kind of compounds do metal form with non metallic elements?
ionic compounds
what are examples of amphoteric oxides?
Lead (Pb)
Aluminium ( AL )
Zinc ( Zn )
what are alloys?
alloys is a mixture of a metal and other elements ( can be metal/ non metal )
what are 3 examples of alloys?
mild steel - iron & carbon
brass - copper & zinc
bronze - copper & tin
why are pure metals soft?
pure metals are soft as the atoms are orderly arranged in layers and the layers of atoms can slide over one another easily when a force is applied
why are alloys stronger than pure metals?
alloys are made up of atoms of different sizes. This disrupts the orderly layers of atoms making it harder for the layers of atoms to slide over each other when a force is applied.
what are the 3 uses of alloys?
1) mild steel. - iron & carbon -> strong & malleable
[ car bodies , steel rods ]
2) stainless steel - nickel , iron , chromium, carbon [NICC] -> non corrosive , rust resistant [ cutlery , utensils & surgical instruments ]
3) brass - copper & zinc -> non corrosive
[ coins , decorative ornaments ]
what is the reactivity series?
measures how readily a metal give up electrons to form positive ions
do reactive metals lose or gain electrons more readily?
lose -> to form positive ions
what are the only metals that reacts with COLD WATER?
P otassium ( explosive ) K
S sodium (explosive) Na
C alcium (vigorously) Ca
M agnesium ( slow ) Mg
(Please Stop Calling Me)
metals below what element don’t react with water, steam or acids?
hydrogen H
copper Cu
silver Ag
gold Au
[ these three metals are unreactive ]
reactive metals + water forms?
metal hydroxides + H2
reactive metals + steam forms?
metal oxides + H2
metals + acid forms?
salt + H2
is it easier or harder to extract a reactive metal from its ore?
harder ( a less reactive metal is easier to extract than a more reactive metal )
what are the two methods to extract metals?
- reduce metal compounds to metal by using carbon
- use electricity to decompose the molten metal compound to the metal ( electrolysis )
in what way can we extract reactive metals such as potassium, sodium, calcium , magnsium and aluminiun?
electrolysis
can unreactive metals be found combined or uncombined on earth?
uncombined
the more reactive a metal is , the more _____ it is
stable
why is electrolysis used on very reactive metals?
-metals are very reactive and hence they are found in very stable compounds with strong ionic bonds.
- a lot of energy is needed to overcome the ionic bonds and so electrolysis of molten ore is used.
what are the examples of very reactive metals?
P otassium (K)
S odium (Na)
C alcium (Ca)
M agnesium (Mg)
what are the examples of LESS reactive metals?
Z inc (Zn)
I ron (Fe)
T in (Sn)
L ead (Pb)
H ydrogen (H)
C opper (Cu)
S ilver (Ag)
G ood (Au)
why is reduction of oxides using carbon or hydrogen used in extracting less reactive metals?
- metals are found in less stable compounds with fairly strong ionic bonds
- lesser energy is needed to break the bonds and so reduction of oxides using carbon or hydrogen is used.
gold in an unreactive metal. what methods can be used to extract gold?
physical methods
