C3 - Structure And bonding Flashcards
What do elements form when they react together?
Compounds
How does elements form a compound?
By gaining or losing electrons or by sharing them
How does the electrons group effect what the elements react with.
Elements only react with the corresponding group. Etc the elements in group 1 react with the elements in group 7.
What type of bond is formed by sharing electrons
Covalent bond
What type of bond is formed of gaining or losing electrons
Ionic bond
When non-metals react with metals which bond do they create
Ionic bonds
Why do elements form ions
To achieve the stable electronic structure of a noble gas
What happens to the charge of an element when an electron is gained or lost
If an electron is gained. The charge is negative.
If an electron is lost the charge is positive
What is the number of electrons which create a full outer shell.
1st shell - 2
2nd shell - 10 (8 in that shell)
3rd shell - 18 (8 in that shell)
And the each shell on has another 8.
Which elements gain or lose an electron during ionic bonding
\+ = positive. - = negative Group 1 form 1+ ions Group 2 form 2+ ions Group 3 for,s 3+ ions Group 4 don't share electrons Group 5 form 3- ions Group 6 form 2- ions Group 7 form 1- ions
How are ionic compunds held together
Ionic compounds are held together by strong forces of attraction between their oppositely charged ions. This is called ionic bonding.
Why are all ionic compounds solid at room temperature
They have a high melting point because it takes a lot energy to break the many strong ionic bonds, operating in all directions, that hold a giant ionic lattice together.
Can ionic compounds conduct electricty
Ionic compunds will conduct electricty when molten or dissolved in water. This is because their ions can then become mobile and can carry charge through liquid.
They only conduct electricty when molten or in a solution not in a solid.
What structure are ionic compunds in?
Giant structure of ions arranged in a lattice. The attractive electrostatic forces between the oppositely charged ions act in all directions and are very strong.
What bond is formed when two non-metals share pairs of electrons with each other
Covalent bond. Each shared pair of electrons is a covalent bond.
Why do elements covalent bond
They share electrons to create a full outer shell. It has to be a pair of electrons.
Structure of covalent bonds
Many substances containing covalent bonds consist of simple molecules but some have giant covalent structures
What are the melting and boiling points of substances made up of simple molecules
They have low melting and boiling points because the intermolecular forces between them are weak.
Can simple molecules conduct electricty?
Simple molecules have no overall charge, so they cannot carry electrical charge. Therefore, substances made of simple molecules do not conduct electricty
What are polymers
Polymers are made up of many small reactive molecules that bond to each other to form long chains. The inetrmolecukar forces are relatively high compared to smaller molecules.
What are giant covalent structures
Some substances which didn’t have a relatively small number of atoms arranged in simple molecules. They instead form huge networks atoms held together by strong covalent bonds in giant covalent structures
Examples of substances with giant covalent structures
Diamond, graphite and silicon dioxide
Properties of substances with giant covalent bonds
Very high melting and boiling points
Insoluble in water
Apart from graphite, they are hard and do not conduct electricity
Whats the difference between the bonds in graphite and the bonds in diamond?
In graphite there are no covalent bonds between the layers. This means they can slide over each other, making graphite soft and slippery. However, the carbon atoms in diamond have a figid giant covalent structure, making it a very hard substance.
