topic 6 Flashcards
(23 cards)
the alkali metals is what group
group 1
what are the alkali metals ?
lithium sodium potassium rubidium caesium francium
how many outer electrons do alkali metals have ?
one meaning they have similar chemical properties
what are the physical properties of alkali metals ?
low melting + boiling point
very soft
going up or down ? which way do alkali metals get more reactive
down as electron becomes easier to loss as it is further from the nucleus
how do alkali metals react ?
very vigorously
what group are the halogens ?
7
what are the halogens ?
fluorine. chlorine bromine iodine astatine
how many electrons do halogens have in outer shell ?
7 electrons do they have similar chemical properties
TRUR or FALSE Halogens exist as diatomic molecules ?
yes - they also come in two
what happens when halogens react with metals and hydrogen
with metal they form salts
with hydrogen they form hydrogen halides
going up or down makes halogens more reactive ?
going up increases reactivity since it is harder to attract electrons
as halogens go down what increases ?
their melting/boiling points and colours get darker
when alkali metals react with water what is produced?
the alkali hydroxide and hydrogen
how do you test for chlorine?
by holding a damp blue litmus paper over the gas. if it turns white or bleaches it then chlorine is present
what group is the noble gases ?
group 0
what are the noble gases ?
helium neon argon krypton xenon radon
TRUE or FALSE group 0 elements are inert
true since they have a full outer shell of electrons
properties of noble gases
colourless
they’re inert
non-flammable
name a use of noble gases
used in filament lamps to stop hot filament from burning away.
used as inert atmosphere to stop welded metal reacting with oxygen
helium has lower density than oxygen so it helps balloons float and airships
as you go down group 0 what increases?
boiling/melting points
density
what are displacement reactions ?
a displacement reaction is where a more reactive element pushes a less reactive element in a compound
what kind of reaction is a displacement reaction ?
a redox
halogens gain electrons.
while halides lose electrons
