Y10 Topic 1-bonding Flashcards
Why do ionic substances have such high melting/boiling points?
Ionic substances have high melting and boiling points as they have full outer shells meaning they have strong electrostatic forces which you need a lot of energy to break .
What are the three types of bonding
Covalent bonding
Ionic bonding
Metallic bonding
Why can ionic substances only conduct electricity when they are in a liquid state ?
This is because ionic substances have weaker electrostatic forces when they are liquid and so the electrons are free to move around and pass on charge
Can ionic substances conduct electricity in a solid state
No , as the electrostatic force is too strong so the electrons aren’t free to move or pass on charge
How many electrons does an element have if it is in:
A) group 3
B)group 4
C)group 7
A)3
B)4
C)7
Name the diatomic elements
All of group 7
And oxygen , hydrogen , nitrogen
Name the 3 types of subatomic particles
Protons
Neutrons
Electrons
What is an ion
An ion is an atom that has lost or gained electrons
What are electrostatic forces
An extremely strong force between 2 oppositely charged ions which can make it very hard to separate them. (Also the force between nucleus and electrons that keeps an atom together)
Ionic bonding occurs between…?
Metals and non metals
What is a covalent bond
A covalent bond is a shared pair of electrons
What is a molecule
A particle made from atoms joined by a covalent bond
What are the properties of a giant covalent structure?
Diamond - high melting/boiling points
V strong carbon bonds
Does not conduct electricity
Graphite - v slippery b/c of gaps between layers of atoms
Solid
Conducts electricity
Why can graphite conduct electricity?
Because each carbon is only bonded to 3 other carbons so there are free electrons along its layers of atoms to conduct electricity
What is an allotrope & give an example
A substance which is made from the same atom as another substance however it’s molecular structure is very different eg diamond and graphite are allotropes of carbon
Why is graphite sometimes used as a lubricant?
Graphite is bonded by covalent bond, so it has weak intermolecular forces and is also arranged in sheets of hexagonal units which have gaps between layers which makes it easy for layers to slide off so graphite would be slippery and soft enough to act as a lubricant.
Can diamond conduct electricity?
No as it has no free electrons
Why would fluorine have a low boiling point ?
It is a simple molecular structure and therefore has weak intermolecular forces which require small amounts of energy to break
What are carbon , silicon dioxide and diamond?
Giant atomic structures
What do sodium and chlorine react together to make?
Salt ( NaCl )
What does fullerene mean?
The fullerenes are a large class of allotropes of carbon and are made of balls, ‘cages’ or tubes of carbon atoms
What is a catalyst?
A substance that speeds up a reaction by providing an alternative route with a lower activation energy and does not get used up in the process.
Metallic bonding occurs between …?
Metals and metals
When metals are bonded together what do they make?
A sea of delocalised electrons and an array of positive ions
