Bonding, Structure And The Properties Of Matter Flashcards
What are the three types of strong chemical bonds?
Ionic, covalent and metallic
For ionic bonding how are the particles charged?
The particles are oppositely charged ions
For covalent bonding what are the particles?
The particles are atoms which share pairs of electrons
For metallic bonding what are the particles?
The particles are atoms which share delocalised electrons
Where does ionic bonding occur?
Ionic bonding occurs in compounds formed from metals combines with non- metals
Where does covalent bonding occur?
In most non-metallic elements and in compounds of non-metals
Where does metallic bonding occur?
Metallic bonding occurs in metallic elements and alloys
What sort of compound is a giant structure of ions?
Ionic compound
What are ionic compounds held together by?
By strong electrostatic forces of attraction between oppositely charged ions
What is it called in when all strong electrostatic forces of attraction act in all directions in the lattice?
Ionic bonding
An ionic compound is any compound that only contains what?
Ionic bonds
What is the structure of ionic compounds called
Giant ionic lattice
What do the ions in ionic compounds form?
The ions form a closely packed regular lattice arrangement
Why do all ionic compounds have high melting points and high boiling points?
Because of the many strong bonds between the ions. It takes a lot of energy to overcome this attraction
When ionic compounds are solid, what happens ?
The ions are held in place so the compounds can’t conduct electricity
What happens when ionic compounds melt?
The ions are free to move and they’ll carry electric current
What happens when some ionic compounds dissolve easily in water?
The ions separate and are all free to move in the solution so they’ll carry electric current
How do you find the empirical of an ionic compound from a diagram of the compound?
If it’s a dot and cross diagram, count up how many atoms there are of each element. Write it down to give you the emotional formula.
If it’s a 3D diagram of the ionic lattice, use it to work out what ions are in the ionic compound.
Then balance the charges of the ions so the overall charge on the compound is 0.
Ions are made when electrons are what?
Transferred
Are ions charged particles? Can they be single atoms or groups of atoms?
Yes ions are charged particles and they can be single atoms or groups of atoms
Atoms with full outer shell are very what
Very stable
What are atoms trying to do when the lose or gain electrons to form ions?
They’re trying to get a full outer shell
What happens when metals form ions?
They lose electrons from their outer shell to form positive ions
What happens when non-metals form ions?
They gain electrons into their outer shell to form negative ions
The number of electrons lost or gained is the same as what?
The same as the change on the ion
What happens when a metal and a non-metal react together?
The metal atom loses electrons to form a positively charged ion and the non-metal gains these electrons to form a negatively charged ion
What is it called when oppositely charged ions are strongly attracted to one another by electro static forces?
This attraction is called an ionic bond
What groups are the most likely to form ions?
Groups 1 & 2 and 6 & 7
Group 1 and 2 elements are metals and they lose electrons to form what?
To form positive ions (cations)
Group 6 and 7 elements are non-metals. They gain electrons to form what?
To form negative ions (anions)
Elements in the same group all have the same number of outer electrons. So they have to lose or gain the same number to get a full outer shell. And this means that they form ions with what?
They form ions with the same charges.
What ions do group 1 elements form?
1+ ions
What ions do group 2 elements form?
2+ ions
What ions do group 6 elements form?
2- ions
What ions do group 7 elements form?
1- ions
A sodium atom (Na) is in group 2 so how many electrons does it lose to form a sodium ion with the same electronic structure as neon?
It loses 1 electron
A magnesium atom (Mg) is in group 2 so how many electrons does it lose to form a magnesium ion with the same electronic structure as neon?
It loses 2 electrons
A chlorine atom (Cl) is in group 7 so how many electrons does it gain to form a chloride ion with the same electronic structure as argon?
It gains 1 electron
An oxygen atom (O) is in group 6 so how many electrons does it gain to form and oxide ion with the same electronic structure as neon?
It gains 2 electrons
What do atoms form when they share pairs of electrons?
They form covalent bonds. These bonds between atoms are strong
What can covalently bonded substances may consist of?
Small molecules
Some covalently bonded substances have very large what?
Very large molecules such as polymers
Some covalently bonded substances have giant covalent structures such as what?
Such as diamond and silicon dioxide
What is covalent bonding?
Where atoms share electrons with each other so that they’ve got full outer shells
What happens when non-metal atoms bond together?
They share pairs of electrons to make covalent bonds
The positively charged nuclei of the bonded atoms are attracted to the shared pair of electrons by what, making covalent bonds very what?
By electrostatic forces, making covalent bonds very strong
Each single covalent bond provides one extra what for each atom
One extra shared electron
Where does covalent bonding happen?
It happens in compounds of non-metals and in non-metal elements
What are the different ways of drawing covalent bonds?
Dot and cross diagrams
Displayed formula
3D model
Hydrogen atoms have just one electron. How many more do they need to complete the first shell?
One so they often form single covalent bonds either with other hydrogen atoms or with other elements
How many more electrons does each chlorine atom need to complete the outer shell?
Just one so two chlorine atoms can share one pair of electrons and form a single covalent bond
How many more electrons does each oxygen atom need to complete its outer shell?
Two more so in oxygen gas two oxygen atoms share two pairs of electrons with each other making a double covalent bond
How many more electrons does a nitrogen atom need to complete its outer shell?
Three more electrons so two nitrogen atoms share thee pairs of electrons to fill their outer shells. This creates a triple bond
Substances containing covalent bonds usually have what structures?
Simple molecular structures
The atoms within the molecules are held together by what?
Very strong covalent bonds but the forces of attraction between these molecules are very weak
What do you need to do to melt or boil a simple molecular compound?
You only need to break the feeble intermolecular forces and not the covalent bonds.
Why are the melting and boiling points of simple molecular compounds very low?
Because the molecules are easily parted from each other
Most molecular substances are what at room temperature?
Gases or liquids
As molecules get bigger the strength of the intermolecular forces does what?
Increase
Why does the melting and boiling points increase as molecules get bigger?
Because as the strength of the intermolecular forces increase, more energy is needed to break them
Why don’t molecular compounds conduct electricity?
Because they aren’t charged so there are no free electrons or ions
