Chapter 3 - Chemical Bonding Flashcards
(22 cards)
what is an element?
a substance that cannot be further divided into simpler substances by chemical methods; contain the same number of protons
what are metals?
a class of chemical elements (and alloys) that all have a characteristic shiny appearance and are good conductors of electricity
what are non-metals?
a class of chemical elements that are typically poor conductors of electricity and heat
what is a compound?
a substance formed by the chemical combination of two or more elements in a fixed proportion
what is a chemical formula?
a shorthand method of representing chemical elements and compounds using the symbols of the elements
what is meant by chemical bonding?
the strong forces that hold atoms (or ions) together in the various structures that chemical substances can form - metallic bonding, ionic bonding and covalent bonding
what are diatomic molecules?
molecules containing two atoms
what is covalent bonding?
chemical bonding formed by the sharing of one or more pairs of electrons between two atoms
what is a dot-cross-diagram?
a diagram drawn to represent the bonding in molecules or the electrons in an ion; usually only the outer electrons are shown
what is ionic bodning?
a strong electrostatic force of attraction between oppositely charged ions
what are ions?
charged particles made from atoms or groups of atoms (compound ions) by the loss or gain of electrons
what are electrostatic forces?
strong forces of attraction between particles with opposite charges such as forces involved in ionic bonding
what are cations?
a positive ion that would be attracted to the cathode in electrolysis - lose electrons (metals)
what are anions?
a negative ion that would be attracted to the anode in electrolysis - gain electrons (non-metals)
what is meant by giant ionic lattice (structure)?
a lattice held together by the electrostatic forces of attraction between positive and negative ions
what are giant structures?
lattices where the structure repeats itself in all directions; the forces involved are the same in all directions holding the whole structure together
what is meant by giant covalent structures?
a substance where large numbers of atoms are held together by covalent bonds forming a strong lattice structure
what is meant by giant metallic lattice?
a regular arrangement of positive metal ions held together by the mobile ‘sea’ of electrons moving between the ions
what is meant by the term ‘sea’ of delocalised electrons?
term used for the free, mobile electrons between the positive ions in metallic lattice
what is meant by metallic boding?
an electrostatic force of attraction between the mobile ‘sea’ of electrons and the regular array of positive metal ions within a solid metal
what is meant is something is malleable?
can be bent and beaten into sheets
what is meant is something is ductile?
can be drawn out and stretched into wires
