The Periodic Table Flashcards
What is the Periodic Table?
A collection of all known elements
What order is the Periodic Table arranged in?
Ascending atomic number from left to right
What are groups on the Periodic Table?
The vertical columns
What are periods on the Periodic Table?
The horizontal rows
How can the electron configuration of an element be determined?
By its position on the Periodic Table
What is the special name given to elements in group 1 (I)?
Alkali metals
What special name is given to elements in group 2 (II)?
Alkaline earth metals
What special name is given to elements in group 17 (VII)?
Halogens
What is the special name given to elements in group 18 (VIII)?
Noble gases
What is a diatomic element?
An element which, in its elemental state, bonds to itself
Which elements are diatomic?
The halogens
Nitrogen
Oxygen
Hydrogen
What kind of ions do metals usually form?
They generally lose electrons easily
So they form positive ions
How many valence electrons do metals have?
Generally they have few valence electrons
Where are metals found?
Left hand side of the Periodic Table (except H)
Where are non-metals found?
On the right hand side of the periodic table
How many valence lecterns do non-metals have?
Generally, they have many valence electrons
Which elements are stable?
The noble gases
Why are noble gases stable?
All of their energy levels are filled
They do not have any unpaired electrons
What do all atoms try to do?
Become stable
How do atoms attempt to become stable?
They try to match the electron configuration of the stable elements
i.e They try to have all of their energy levels filled
How do atoms make all of their electrons filled?
By gaining or losing electrons (forming ions)
What charge will elements in group I try to form?
A positive charge of one
i.e they will try to lose an electron
What charge will elements in group II try to form?
A positive charge of two
i.e they will try to lose two electrons
What charge will elements in group III try to form?
A positive charge of three
i.e. They will try to lose three electrons
What kind of charge will elements in group IV try to form?
Either positive or negative charges of four, depending
i.e they will either try to lose or gain four electrons
What kind of charge will elements in group V try to form?
A negative charge of three
i.e They will try to gain three electrons
What kind of charge will elements in group VI try to form?
A negative charge of two
i.e they will try to gain two electrons
What kind of charge will elements in group VII try to form?
A negative charge of one
i.e they will try to gain one electron
What causes the gradually changing properties of elements in a given period?
The gradually changing valence electron configuration
What is atomic radius?
The distance from the centre of the nucleus to the outermost electron
What happens to atomic radius as you move from the left of a period to the right?
It decreases
Why does atomic radius decrease as you move from left right on the Periodic Table?
There are more protons
The attractive force on the lecterns is also greater
The electrons move closer to the nucleus
The radius decreases
What happens to atomic radius as you move down the groups on the Periodic Table?
It increases
Why does atomic radius increase as you move down the groups on the Periodic Table?
Energy levels are added
The electrons are therefore further away from the nucleus
What is density?
Mass per unit volume
How heavy something is in relation to the amount of space it occupies
Are metals or non-metals generally more dense?
Metals
What happens to the density of metals as you move from left to right on the Periodic Table?
Increases
In which groups does moving from left to right increase melting and boiling points?
Groups 1-14
What is the general melting and boiling point for elements in groups 15-18?
Low
As you move down in group 1 and 2, what happens to the melting and boiling points?
Decrease
As you move down in group 17 and 18, what happens to the melting and boiling points?
Increase
What does ionisation energy concern?
The formation of cations
What is ionisation energy?
The energy required to remove an electron from a single atom in the gaseous phase
What is first ionisation energy?
The energy required to remove one electron
What is second ionisation energy?
The energy required to remove the second electron
What happens to first ionisation energy as you move from left to right?
It increases
What happens to first ionisation energy as you move down a group?
Decreases
Why does first ionisation energy increase as you move across a period?
More protons means a greater force of attraction on the electrons
Need more energy to overcome this force
Why does first ionisation energy decrease as you move down a group?
More energy levels
Force of attraction is weaker
Less energy required to break it
What does electrons affinity concern?
The formation of anions
What is electron affinity?
The amount of energy liberated (released) when an electron is added to a single atom in the gaseous phase
What happens to electron affinity when you move across a period?
Increases
What happens to electron affinity when you move down a group?
Decreases
Why does electron affinity increase as you move across a period?
The attraction for an electron is greater
Why does electron affinity decrease when you move down a group?
The attraction for an electron decreases
What does electron negativity concern?
The formation of shared electron pairs (covalent bonds)
What is electron negativity?
The attractive force that an atom has on a shared electron pair
How is electronegativity measured?
On a scale of 1-4
What happens to electronegativity as you move across a period?
It increases
What happens to electronegativity as you move down a group?
It decreases
Why does electronegativity increase as you move across a period?
More protons
Greater force can be exerted on the electron pair
Why does electronegativity decrease when you move down a group?
Extra energy level
The electron pair is further from the nucleus
Can’t exert as great a force
Which element has the greatest electronegativity?
Fluorine
Why does Fluorine have the greatest electronegativity?
It has the most protons in its period, but the fewest energy levels in its group
Which group is the most reactive?
Group I
Alkali Metals
Why is Group I the most reactive?
All the elements in this group only have one valence electron
It is eager to give up this electron, so chemical reactions happen easily
Where are alkali metals naturally found?
In compounds
How are the elemental forms of alkali metals stored?
In inert liquids, to prevent reactions from occurring
How do alkali metals react with cold water?
They produce hydrogen and a hydroxide
What happens to the reactivity of group I as you move down the group?
Increases
What does the group number of an element tell us?
The number of valence electrons an element has (except He)
Which two groups have their valence electrons in s-Orbitals?
I and II
Which groups have their valence electrons in p-Orbitals?
III to VIII (except He)
What tells us the number of energy levels that an element has?
The period number
What do the alkali metals look like?
Soft and grey
What are the alkali earth metals like?
Very similar to alkali metals
Just slightly less reactive
What do alkali earth metals do when in contact with cold water?
Except for Be, they form a hydroxide and hydrogen
What do alkali earth metals look like?
Apart form Be, they are light grey and soft
What is the reactivity of the halogens like?
High
Why is the reactivity of halogens high?
They only need one electron to reach the ‘stable’ state
What do the halogens form when reacting with metals?
Salts
What happens to the reactivity of the halogens as you move down the group?
Decreases
Why does the reactivity of the halogens decrease as you move down the group?
The atomic radius increase
The force of attraction on the electrons decreases
What are the melting points of the halogens like?
Low
What is the reactivity of group 18 like?
Very low
Why are the elements in group 18 called the noble gases?
They don’t tend to bond with anything
They are all gases at room temperature
How are the charges of atoms shown?
With a superscript number in the top right hand corner of the chemical symbol
The number of the charge is shown, as well as the type (+ / -)
