Summarised Flashcards
What group are noble gases
0
Name the 5 noble gases and their uses
Helium - balloons
Neon - lights
Argon - lightbulbs
Krypton- high efficiency miners lamps
Radon - radioactive research
What group are alkali metals and name them
Group 1, lithium, sodium, potassium, calcium, francium
Why does reactivity increase down the alkali metal group?
Reactivity increases as the negative electron in the valence is further away from the positive nucleus. It is therefore less attracted and can be lost easily.
What are the observations of placing lithium, sodium, potassium and rubidium in water?
Lithium - fizzing, moving as well
Sodium - small spark and more fizzing
Potassium - bigger explosion lilac flame
Rubidium- huge explosion
What group are the halogens
7
What happens to the reactivity down the halogens and why?
The reactivity decreases down the group as the attraction of the nucleus to the outer shell is weaker, making it harder to gain an electron in outer shell
What are endothermic reactions?
This is when energy is taken in from surroundings
What are exothermic reactions?
This is when energy is released to surroundings
State 2 examples of endothermic reactions
Thermal decomposition and sport injury packs
State 3 examples of exothermic reactions
Combustion, many oxidation reactions, neutralisation
What is ionic bonding?
This occurs between a non metal and a metal, the metal loses electrons and the non metal gains electrons
What is covalent bonding?
This occurs between 2 non metals where they share electrons. It forms molecules.
What is the difference between small and large covalent structures
Small - tend to be gases, have less elements, lower melting points and weak intermolecular forces.
Large - tend to have more elements with lots more bonds. Higher melting points and higher intermolecular forces.
State the properties of silicon dioxide ( sand )
Each bond is joined to 4 other silicon elements, insoluble, doesn’t conduct electricity, high melting point.
State the properties of graphite.
Carbon atoms are joined to 3 other atoms in hexagonal columns, these are layered, conducts electricity and has a high melting point
Why can graphite conduct electricity
Graphite has delocalised electrons, just like metals. These electrons are free to move between the layers in graphite, conducting electricity.
State the properties of diamond
Each carbon atom is bonded to 4 others, hard, doesn’t conduct electricity, high melting point
What is a fullerene
This is 60 carbon atoms joint in a spherical structure.
What is the first fullerene known as?
Buckminsterfullerene
What is a graphene?
This is 1 layer of graphite in a hexagonal structure.
What forces are between ionic bonds’
Electrostatic
What forces are between covalent bonds?
Intermolecular
If an element is below carbon in the reactivity series what happens?
Carbon displaced it.
