C2 Flashcards
Define relative atomic mass
The weighted average mass of an atom of an element compared to 1/12th of the mass of a carbon-12 atom
Define relative formula mass
The sum of the relative atomic masses of all atoms in a formula
Define relative molecular mass
The sum of the relative atomic masses of all atoms in a molecular formula
How do you calculate relative formula masses?
By summing the relative atomic masses from the formulae and from balanced equations
What is the empirical formula of a compound?
The simplest whole number ratio of atoms of each element in a compound
What does purity mean?
Purity refers to the absence of impurities in a substance; many useful materials are mixtures
How can melting point data be used?
To distinguish pure from impure substances based on melting point range
What is filtration?
A purification method that separates solids from liquids using a barrier
What is crystallisation?
A purification method that forms solid crystals from a solution
What is simple distillation?
A method to separate a liquid from a solution based on boiling point
What is fractional distillation?
A method to separate mixtures of liquids with different boiling points
What are suitable purification methods?
Methods suggested based on the properties of the substances involved
How does chromatography work?
A technique to separate components of a mixture based on their movement through a medium
What are R values in chromatography?
The ratio of the distance traveled by the substance to the distance traveled by the solvent front
What are suitable chromatography methods?
Methods used to distinguish pure from impure substances based on their movement in the medium
How can you distinguish between metals and nonmetals?
By comparing their physical and chemical properties
What is the electronic structure of an element?
The arrangement of electrons in an atom
How is an element’s position in the Periodic Table linked to its electronic structure?
Elements are arranged by increasing atomic number, reflecting their electron configurations
How do ions form?
By the loss or gain of electrons by atoms
What are covalent bonds?
Chemical bonds formed by the sharing of electron pairs between atoms
What are dot-and-cross diagrams?
Diagrams representing the arrangement of electrons in ionic compounds and simple molecules
What are the structures of ionic compounds?
Consist of a regular lattice structure of ions held together by electrostatic forces
What are giant covalent structures?
Large networks of covalently bonded atoms, such as diamond or graphite
What are the properties of metals?
Good conductors of electricity and heat, malleable, ductile
