C2.3 Flashcards
3 subatomic particles and their masses
Mass
Protons 1
Neutrons. 1
Electrons. Very small
What is an isotope
Different atomic forms of the same element, which have the same number of protons but a different number of neutrons
What is ionic bonding
Transferring electrons
Atoms lose or gain electrons to form charged particles (ions) which are then strongly attracted to one another
What is a compound
Compounds are formed when two or more elements are chemically combined together
What is the structure of an ionic compound and what are their properties
Regular lattice
High melting points
High boiling points
Carry a electric current
Strong bond between ions so a lot of energy needed to break apart
When melted ions are free to move
What is covalent bonding
Sharing electrons
Giant covalent structure
Diamond properties
Very rigid structure making it the gardens natural substance
Used for drill tips
Giant covalent structure
Silicon dioxide
What sand is made of
Giant covalent structures
Graphite
Layers that slide over each other
Soft and slippery
Weak intermolecular forces
Good conductor of heat and electricity (delocalised electron)
Metallic structures
Sea of free electrons
Relative formula mass
The atomic numbers added together
Number of moles
Number of moles= Mass in g / relative f m
Calculating % mass of an element in a compound
Percentage mass= Ar x no. of atoms / Mr x100
Calculating masses in reactions (3 steps)
Write out balanced equation
Work out Mr
Apply: divide to get one, then multiply to get all
Percentage yield compares actual and predicted yield
% yield= actual yield g / predicted yield x10
