BTEC Applied science Unit 1 A1 Chemistry 2022/2023

Metallic bonding electrostatic attraction between postive ions and delocalised electrons Ionic bonding strong electrostatic attraction between oppositely charged ions Covalent bonding strong electrostatic attraction between two nuclei and the shared pair(s) of electrons between them Atomic number Number of protons Mass number number of protons and neutrons Malleable Can be hammered into shape Ductile Can be drawn into a wire Electronegativity Ability of an element to attract electrons in a covalent bond Hydrogen bond Attraction between an O-H, N-H or F-H bond and a lone pair of electrons Polar bond a covalent bond where one element is more electronegative than the other van der Waals Weak force of attraction between molecules Dipole When a molecule has a slight positive and negative charge that hasn't cancelled out. Dipole-dipole Where polar molecules interact, the slight positive charge on one molecule attractive the slight negative charge on another. Dative covalent (coordinate) bonding A covalent bond where both electrons come from the same atom. relative atomic mass average mass of one atom of an element relative to one twelfth of the mass of an atom of carbon-12 relative molecular mass average mass of a molecule relative to one twelfth of the mass of an atom of carbon-12 lattice regular arrangement of atoms, ions or molecules cation postive ion anion negative ion