Chapter 13 Behavior of metals Flashcards
what are group 1 metals called
alkali metals
how does reactivity change down the group and why (group 1)
reactivity increases
there is a lesser force of attraction between the outer shell electron and the nucleus, as the shell number increases the force of attraction will decrease making it easier to give the electron away.
how does the melting and boiling point change down the group and why (group 1)
melting and boiling point decrease down the group
as the reactivity increases, it is easier to break the bonds hence making it easier to melt or boil
how does the softness change down the group and why (group 1)
softness increases
as the reactivity increases, the bonds become easier to break, making the metal softer and easier to cut
how does the density change down the group and why (group 1)
density increases
as the mass number increases there will be more particles per unit volume increasing the density
what are group 2 metals called
alkaline earth metals
what are the trends as you go down the group (group 2 metals)
melting and boiling point decrease
density increase
softness increase
reactivity increase
difference between alkali metal and alkaline earth metal
not as reactive as group 1 metals
and form 2+ ions
what are halogens
halogens are the most reactive non-metals
which group are halogens in
group 7
which ions do halogens form
-1
how does reactivity change down the group and why (halogens)
reactivity decreases
as the shell number increases the force of attraction between the nucleus and the outer electron decreases, halogens take electrons and don’t give hence making it harder to gain the electron decreasing the reactivity
how does the intensity of the colour change down the group(halogens)
colour intensity increases (gets darker)
name the elements and the colours down the group in this group (halogens)
flourine/chlorine is greenish-yellow
bromine is orange-brown
iodine is dark brown
astatine is black
how does the melting and boiling point change down the group and why(halogens)
increases
as it gets less reactive it is harder to gain an electron
making the bonds harder to break causing there to be a higher temperature needed to break the bonds
how do the states of the elements change in halogens down the group
first two elements are gaseous (flourine and chlorine)
bromine is liquid
iodine and astatine are solid
how does density vary down the group
density increases
as the mass number increases there will be more particles per unit volume increasing the density
what are noble gases also known as
inert gases
how do noble gases react
they are unreactive
which group are they in (noble gasses)
group 8
how does melting and boiling point vary down this group and why (group 8)
increase
as the gases get heavier it is harder to vaporise, causing there to be a need in higher temperature supplied to vaporise the element
how does density vary down the group 8
density increases
as the mass number increases there will be more particles per unit volume increasing the density
properties of metals (physical)
high density
malleable
ductile
strong
shiny
conductor of heat
conductor of electricity
sonorous
high melting
high boiling
chemical properties of metals with oxygen
acidic or basic
all metals react with oxygen to form metal oxide (metal oxides are basic in nature)
chemical properties of metals with acid
metal + acid —> salt + hydrogen
chemical properties of metals with water
metal + water –> metal hydroxide + hydrogen
some of the metal that doesn’t react with water forms metal oxide + hydrogen
transition metal chemical properties
variable valencies
compounds of transition metals are coloured
used as catalysts
metal + water –> metal hydroxide + hydrogen
metal + acid —> salt + hydrogen
metal + oxygen –> metal oxide
chemical property of metals when reacted with non-metals
form ionic compounds
which metal is the most reactive with water and what does it form
potassium
reacts violently with cold water (catches fire)
products: hydrogen, KOH (K + h2o –> KOH + H2)
which metal is the second most reactive with water and what does it form
sodium
violent with cold water
products: hydrogen, NaOH (Na + h2o –> NaOH + H2)
which metal is the third most reactive with water and what does it form
calcium
less violent with cold water
products: hydrogen, calcium hydroxide (Ca + h2o —> Ca(OH)2 + H2)
how can we compare metals reactivity
reacting them with the same reactant. If one metal is more reactive than the other it will react faster and more vigorously, at a lower temperature
which metal is the most reactive with hcl and what does it form
magnesium
products: hydrogen, magnesium chloride (Mg + HCl —> MgCl2 + H2)
which metal is the second most reactive with hcl and what does it form
zinc
products: hydrogen, zinc chloride (Zn + HCl —> ZnCl2 + H2)
magnesium displaces hydrogen when reacted with hcl and when reacted with water what does this mean
this means magnesium is more reactive than hydrogen and has a stronger drive to give away electrons hence having a stronger drive to form compounds
which metal is the most reactive with oxygen and what does it form
sodium
products: sodium oxide (white solid) (Na + O2 —> Na2o)
which metal is the second most reactive with oxygen and what does it form
calcium
products: calcium oxide (white solid) (Ca + O —> CaO)
which metal is the third most reactive with oxygen and what does it form
magnesium
products: magnesium oxide (white solid) (Mg + O —> MgO)
how does the speed of magnesium reacting with water vary
reacts with water slowly but vigorously with steam
in a metals reactivity series why are non-metals hydrogen and carbon present
they are used to extract metals from their oxides
state the reactivity series of metals
potassium
sodium
calcium
magnesium
aluminium
carbon
zinc
iron
hydrogen
copper
silver
gold
list the 4 most reactive metals and their reactions with water (balanced)
potassium
2K + 2H2O —> 2KOH + H2
sodium
2Na + 2H2O –> 2NaOH + H2
calcium
Ca + 2H2O –> Ca(OH)2 + H2
magnesium
Mg + 2H2O –> Mg(OH)2 + H2
which metals react with steam and not water
metals below calcium (magnesium,aluminium,carbon,zinc,iron,hydrogen,copper,silver
gold)
which metals will react with dilute acids
metals above hydrogen
why are some metals more reactive than others
This is because more reactive metals lose electrons and form ions more readily than less reactive metals, making them better reducing agents
what is rusting
chemical compound of rust
Rust is a chemical reaction between iron, water and oxygen to form the compound hydrated iron(III) oxide (which is rust)
which compound and element must be present for rusting to occur
compound: water
element: oxygen
what happens to iron during rusting
iron gets oxidised
what is the “barrier method” of rust protection
Rust can be prevented by coating iron with barriers that prevent the iron from coming into contact with water and oxygen
what are common barrier materials that are used
grease, oil, paint, plastic
which metals can rust, when other metals are broken down in the presence of water and oxygen what is it called.
only iron and an alloy of iron can rust
if any other metal is broken down it is known as corrosion
how can iron be prevented from rusting other than by using a barrier
using a metal that is more reactive than iron causing that metal to oxidise first and corrode
what is galvanising
Galvanising is a process where the iron to be protected is coated with a layer of zinc
how can the layer of zinc be applied on to iron
electroplating or dipping it into molten zinc
what is formed when zinc reacts with air
ZnCO3
explain why a metal is/is not suitable as a method of preventing an iron/steel object from rusting.
if it is higher in the reactivity series than iron, it will be suitable for sacrificial protection as it will be oxidised instead of iron.
If it is lower in the reactivity series than iron, it would not be suitable as iron would be oxidised, causing it to rust.
two ways in which physical properties of transition elements differ from group 1 metals
higher density
higher boiling points
