Bonding and Structure Flashcards
Give the formula for a carbonate ion.
CO3-
Give the formula for a nitrate ion.
NO3-
Give the formula for a sulphate ion.
SO4 2-
Give the formula for an ammonium ion.
NH4+
Give the formula for a phosphate ion.
PO4 3-
Define ionic bonding.
An electrostatic attraction between positive and negatively charged ions.
What is the usual electronic configuration of the positive ion in a compound?
The same as that of the previous noble gas on the periodic table.
What is the usual electronic configuration of the negative ion in a compound?
The same as that of the next noble gas on the periodic table.
Define covalent bonding.
The overlap of atomic orbitals, each containing 1 electron, to give a shared electron pair.
Define a molecule.
A small group of atoms bonded together by covalent bonds.
What is the ‘octet rule’?
The general rule that atoms ideally contain 8 electrons on their outer shells when bonding covalently.
What is a shared pair of electrons called?
A bonding pair.
What is an electron pair that is not involved in bonding called?
A lone pair.
What is a dative covalent bond?
A covalent bond in which both shared electrons come from the same atom.
What kind of structure do ionic compounds form?
Giant ionic lattices.
What is a simple covalent structure?
A small, covalently bonded compound that forms discrete molecules.
What is a giant covalent structure?
An infinite lattice structure of atoms, where each atom is bonded covalently to many neighbouring atoms.
What kind of structures do metals have?
Giant lattice structures.
What property of metal atoms allows delocalised electrons?
A relatively low ionisation energy.
Describe metallic bonding.
A regular lattice structure of positively charged metal ions, held together by a sea of delocalised electrons.
Why do metals have high melting and boiling points?
Strong electrostatic forces between positively charged ions and electrons require a lot of energy to overcome, and therefore high temperatures are needed.
Why do metals conduct electricity?
The delocalised electrons in metals are free to move and therefore carry charge, allowing current to flow.
Why do metals have poor solubility?
Strong electrostatic attractions between positive ions and delocalised electrons require a lot of energy to break in order to dissolve. Metals usually react, rather than dissolve in water.
Why do some metals have higher melting points than others?
The bigger the charge on a metal atom, the stronger the electrostatic forces in the metal are, and the more energy required to overcome them. Different metals carry different charges.
Why are some metals better conductors than others?
Metals with different charges release different numbers of electrons into the sea of electrons. The higher the density of delocalized electrons, the more conductive a material will be.
Define malleable.
Easily hammered into shape.
Define ductile.
Easily drawn into a wire.
What elements are present in stainless steel?
Iron, Chromium and Carbon.
What elements are present in Brass?
Copper and Zinc.