C2a- Bonding and Calculations Flashcards
What is the structure of an ionic compound?
Regular lattice
Always have giant ionic lattice arrangement
Why do simple molecular substances not conduct electricity?
There are no ions so no electrical charge.
What is a double covalent bond?
When 2 pairs of electrons are shared. For example in oxygen gas (02)
What is the mass number?
Total number of protons and neutrons
What is an isotope?
Different atomic forms of the same element, which have the same number of protons but different number of neutrons
What is the atomic number?
Number of protons (and therefore electrons)
What type of bonding do group 1 elements do?
Ionic- lose one election from outer shell.
What are the forces like in an ionic compound?
Very strong electrostatic forces of attraction between oppositely charged ions, in all directions
Ionic bonding is…….
Transferring electrons to form ions which are then strongly attracted to each other
Why is diamond hard?
Each carbon atom has 4 covalent bonds in a very rigid giant covalent structure.
In giant covalent structures the bond between atoms is….
Strong covalent bonds
Do giant covalent structures conduct electricity?
No
Except for graphite
Group 1 elements (alkali metals) form ionic compounds with …….
Non metals
What are the properties of ionic compounds?
High melting and boiling points due to the strong attraction between ions.
Carry electric current when melted as ions are free to move
Dissolve in water. Ions free to move so carry electric current
In methane (CH4) carbon has 4 outer electrons. So it forms ….. Covalent bonds with hydrogen to form methane
4
There are 2 types of covalent substances, what are they?
Simple molecular
Giant covalent
Why can graphite conduct electricity even though it is a giant covalent structure and a non metal?
As each carbon atom has one delocalised electron.
What 2 ways can you make an ionic compound carry an electric current?
Dissolve in water
Melt
What is the melting and boiling point of simple molecular substances like and why?
Very low due to weak intermolecular forces which can be easily broken.
Why are most simple molecular substances gas or liquid at room temp?
Weak intermolecular forces
Isotopes must have the same ………. number but different ……….. numbers.
Atomic
Mass
Give 3 examples of giant covalent structures
Diamond
Graphite
Silicon dioxide
Why can layers of graphite slide over each other?
Each carbon atom only forms 3 covalent bonds, which creates layers which a free to slide over each other. As there are weak intermolecular forces between the layers.
What is the melting/boiling point of a giant covalent structure like?
Very high due to the strong covalent bonds between atoms
What is a covalent bond?
Atoms share electrons (a pair) to become stable
Each covalent bond provides how many extra electrons for each atom?
1
Giant covalent structures are similar to ionic structures (lattices) except that there are no……. ……
Charged ions
In simple molecular substances, what are the forces of attraction like and why?
Between molecules- very weak. However very strong covalent bonds.
