C1, C2, C3 Flashcards
What is a covalent bond?
The attraction between 2 atoms that share 1 or more electrons
What is an ionic bond?
The electrostatic force of attraction between positively and negatively charged ions.
List what happens in an ionic bond
Electrons are transferred
Ions are formed
Between metals and non-metals
High melting/boiling points
Strong electrostatic forces between ions
Conductive when liquid/molten
List what happens in covalent bonding
Electrons are shared
No ions are formed
Between non-metals
Low melting/boiling points
Weak intermolecular forces between molecules
Non conductive-no free electrons
What are intermolecular forces.
The attraction between the individual molecules in a covalently bonded substance.
What is a polymer?
A substance made from very large molecules made up of many repeating units.
What are delocalised electrons?
A bonding electron that is no longer associated with anyone particular atom.
What is fullerene?
Hexagonal rings of carbon atoms which form cage like structures.For example Graphene is a flat hexagonal structure and carbon nanotubes are tubes of hexagonal structures.
What is an alloy?
A mixture of two or more elements, At least one of which is a metal.
What is metallic bonding?
The electrostatic attraction between the positively chargedAtomic nuclei of metal atoms and the delocalised electrons in the metal.
Why are ionic compounds hard?
– Ionic compounds form a giant lattice
– the strong electrostatic forces are very hard to break
Why are ionic compounds brittle?
– When a force is applied layers shift
– therefore the same charges are next to each other causing them to repel and break apart
Why do ionic compounds have high melting/boiling points?
– Ionic compounds for me giant lettuce with strong electrostatic forces between positively and negatively charged ions
– these forces are very hard to break, so they require lots of energy to boil/melt 
Why are ionic compounds soluble (Can dissolve) in water?
– Water particles break up the ionic lattice into the separate ions
– Interrupting the forces between the positive and negative ions
Do ionic compounds conduct electricity when solid, liquid or in solution – When the ionic compound has been dissolved in a liquid?
– Solids cannot conduct electricity because the ions cannot move to carry the charge
– liquid and solutions can conduct electricity because the ions can move to carry the charge

What is an isotope?
It is atoms of the same element with the same number of protons, but a different number of neutrons.
What is the equation for the Rf value in chromatography?
Rf = distance moved by substance / distance moved by solvent
What are the similarities between elements in the same period?
They have the same number of shells. (However elements in different groups have a different number of electrons in the outer shell.)
What does the mass number represent?
The number of protons add neutrons, because electrons don’t weigh anything.
What does the atomic number represent?
The number of protons or electrons (Because they Have the same amount)
How is the modern periodic table arranged?
By atomic number.
Do the melting and boiling points Decrease as you go down group one alkali metals?
Yes, because the metallic bond is weakened enough for the atoms to move more freely and has broken completely boiling point is reached.
What is the properties of alkali metals?
Alkali metals are:
– low density so they float
– Dissolve in water to form a colourless solution
– react with water to produce a hydroxide and hydrogen gas
– Soft
– dull on the outside reacted with oxygen, shiny on the inside
– They form ionic compounds in which the metal ion has a charge of positive one by reacting with non-metals
– Density increases as you go down the group
– They are called alkali metals because they form an alkaline solution when mixed with water
What are the three types of metals?
Alkali, transition and typical metals e.g. iron
