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explain why some elements can be classified as alkali metals
they form alkaline solutions
when they react with water
what group in the periodic table are alkali metals
group 1
explain why some elements can be classified as halogens
they form salts
when they react with metals
what group in the periodic table are halogens
group 7
explain why some elements can be classified as noble gases
they’re all unreactive, non-metal gases
state the physical properties of alkali metals
soft
relatively low melting points
state word reaction of lithium with water
lithium + water → lithium hydroxide + hydrogen
state word reaction of sodium with water
sodium + water → sodium hydroxide + hydrogen
state word reaction of potassium with water
potassium + water + potassium hydroxide + hydrogen
describe pattern of reactivity of alkali metals with water
all alkali metals react vigorously with cold water
all reactions give off hydrogen gas
and produce metal hydroxide
speed and violence of reaction increases
as you go down group 1
demonstrating that reactivity increases as you go down group 1
state key safety points when reacting alkali metals with water
use plastic safety screen
use small pieces of metal
use large volume of water
use tweezers to hold metal
wear thick rubber gloves
explain the pattern in the reactivity of alkali metals with water based on electronic configuration
reactivity increases as you go down group 1
as the atoms get bigger
distance of outermost electron shell from the nucleus increases
attraction between nucleus and outermost electron shell weakens
meaning electrons are lost easier
state colour of chlorine at room temperature
pale green
state physical state of chlorine at room temperature
gas
state colour of bromine at room temperature
brown
state physical state of bromine at room temperature
liquid
state colour of iodine at room temperature
purple-black
state physical state of iodine at room temperature
solid
describe the pattern in physical properties of halogens
melting and boiling points increases
as you go down group 7
explain the pattern in physical properties of halogens
as you go down group 7
molecules become larger
intermolecular forces become stronger
thus more energy is needed to overcome these forces
describe chemical test for chlorine
gently heat the unknown substance in a test tube
hold damp blue litmus paper in the gas given off
chlorine gas will cause the litmus paper to turn red then bleached
describe reaction of halogens with metals
halogens react with some metals
to form ionic compounds
which are metal halide salts
recall what halogens produce
hydrogen halides
state what happens when hydrogen halides dissolve in water
form acidic solutions
describe the relative reactivity of chlorine
chlorine will displace iodine and bromine
in displacement reactions
as reactivity decreases as you go down group 7
describe the relative reactivity of bromine
bromine will displace iodine
and be displaced by chlorine
in displacement reactions
as reactivity decreases as you go down group 7
describe the relative reactivity of iodine
iodine will be displaced by chlorine and bromine
in displacement reactions
as reactivity decreases as you go down group 7
explain why the displacement reactions of halogens are redox
both oxidation and reduction occur in the reaction
with the more reactive halogen acting as the oxidising agent
and thus being reduced
and the less reactive halogen acting as the reducing agent
and thus being oxidised
oxidation definition
loss of electrons
reduction definition
gain of electrons
explain why noble gases are chemically inert compared to other elements
other elements participate in reactions to complete their outer shell
by losing, gaining or sharing electrons
noble gases have full outer shells
making them unreactive and inert
state properties of noble gases
low density
non-flammable
chemically inert
low melting/boiling point
explain how the use of noble gases in balloons depends on their properties
helium is used for filling balloons
as it is less dense than air
and non-flammable
explain how the use of noble gases in lighting depends on their properties
neon and argon are used for lighting
as they emit a bright glow
when electric current passes through them
with their inert nature preventing reactions
that could affect light output
explain how the use of noble gases for welding depends on their properties
argon is used for welding
as its inert nature protects the weld area
from atmospheric gases (oxygen and nitrogen)
which could cause defects in the weld
explain how the use of noble gases in low energy light bulbs depends on their properties
argon is used in low energy light bulbs
as it glows brightly
when a high potential difference is applied
to the argon gas under low pressure
describe the pattern in the physical properties of noble gases
noble gases have low melting/boiling points
boiling/melting point increases as you go down group 0
explain the pattern in the physical properties of noble gases
as you go down group 0, relative atomic mass increases
causing an increase in strong forces of attraction between atoms
increasing the amount of energy needed to overcome these forces of attraction
Note 
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