C4 Flashcards
what are group 1 elements known as?
Alkali metals
what 4 properties do group 1 elements have?
-low densities
-soft
-low melting and boiling points
-very reactive
why are alkali metals very reactive?
they have 1 electron in their outer shell, they easily from a full outer shell by losing it
does reactivity increase or decrease going down the group for alkali metals and why?
increases, the number of electron shells increases which means the attraction to the nucleus decreases
what is produced when an alkali metal reacts with water?
hydrogen gas + metal oxide
what do alkali metals form with non metals?
an ionic compound
what is produced when an alkali metal reacts with oxygen?
metal oxide
what are group 7 elements known as?
halogens
how many electrons do group 7 elements have in their outer shell?
7
what are the 2 properties of halogens?
-gases at room temp (only the top of group 7)
-solids at room temp (only the bottom of group 7)
do the melting and boiling points of halogens decrease or increase as you go down the group and why?
increase with increasing relative atomic mass. larger atoms have stronger intermolecular forces so more energy is needed to turn it into a gas.
does the reactivity in halogens increase or decrease as you go down the group and why?
decrease. halogens gain one electron for a full outer shell, it’s harder down the group because the number of shells decrease, it’s harder to gain an electron because it’s less attached to the positive nucleus.
what do halogens and non metals form?
molecular compounds, they share electrons (covalent bond)
what do halogens form when reacting with metals?
ionic compounds
what is group 0 also known as?
nobel gases
what are nobel gases at room temp?
colourless gases
does the melting point of noble gases increase or decrease as you go down the group?
increase with increasing relative atomic mass. larger atoms have stronger intermolecular forces between them, they need more energy to overcome the forces and turn into a gas.
how do you test for carbon dioxide?
bubble it through limewater, if carbon dioxide is present then the limewater will turn cloudy
how do you test for oxygen?
a glowing splint will relight when exposed to oxygen. place a glowing splint in a test tube of oxygen and the splint will relight
how do you test for hydrogen?
put a lit splint in a test tube of hydrogen and there will be a squeaky pop sound that tells you that hydrogen is present
how do you test for chlorine?
expose it to damp litmus paper.
why are noble gases inert?
they exist as single atoms, they don’t easily form a molecule. they have a full outer shell (stable)
does the melting point of noble gases increase or decrease as you go down the group?
increase with increasing relative atomic mass. larger atoms have stronger intermolecular forces between them, they need more energy to overcome the forces and turn into a gas.
how do you test for hydrogen?
put a lit splint in a test tube of hydrogen and there will be a squeaky pop sound that tells you that hydrogen is present
Which factor determines the reactivity of a metal?
How easily the atoms of that element lose their outer electrons
what is the order of the reactivity series?
please- potassium
send- sodium
crazy-calcium
monkeys-magnesium
and- alluminium
crazy- carbon
zebras-zinc
in-iron
to-tin
hot-hydrogen
countries-copper
signed-sulfur
gordon- gold
p-platinum
what colour is fluorine at room temp?
yellow gas
what colour is chorine at room temp?
green gas
what colour is bromine at room temp?
red-brown liquid
what colour is iodine at room temp?
grey solid
when alkali metals are put in water what is produced?
hydrogen gas and metal hydroxides
what do alkali metals form when they react with non metals?
ionic compounds
when alkalis react with oxygen what do they form?
metal oxides
what are halogens?
non-metals
the halogens at the top of the group 7 are what at room temperature?
gases at room temperature
what are halogens at the bottom of group 7 at room temperature?
solids at room temperature
why does boiling and melting point increase as you go down group 7?
the larger atoms have stronger intermolecular forces between them this means they need more energy to overcome their forces
what do halogens form with other non metals?
molecular compounds (they also form a covalent bond)
when halogens react with metals what do they form?
ionic compounds
when halogens react with metals what do they form?
ionic compounds
A more reactive halogen can…
displace a less reactive one
how can displacement reactions be recognised?
by a colour change
what are nobel gases known as?
-unreactive
-colourless gases at room temperature
why are nobel gases unreactive?
they have a full outer shell of electrons
the melting and boiling points of noble gases…
increase as you go down the group
why do noble gases melting and boiling points increase down the group?
larger atoms have stronger intermolecular forces, so they require more energy to break their bonds
