3 - Bonding Flashcards
What are the three types of inter-atomic bonding
Covalent - Between two non-metals
Metallic - Between two Metals
Ionic - Between a metal and a non-metal
What are the main features of Ionic bonding
Forming salts, the metal will donate an electron to the non-metal, forming two ions, normally both with the electronic structure of noble gases, which are attracted to each other by electrostatic forces, they form solids with lattice structures at room temperature with very high melting points, and are often conductive in solution and when liquid
What are the main features of Covalent bonding
Two non metals will share electrons, forming single, double and triple bonds, allowing the two atoms to obtain noble electronic structures, in simple Covalent molecules, they have low melting and boiling points, and with giant, high melting and boiling points.
What is a co-ordinate or dative bond
one atom provides both electrons in the Covalent bond
What are the main features of Metallic bonding
the outer shell electrons of each metal atom will delocalise, forming a ‘sea of electrons’ with, due to the electrostatic attraction, binds the atoms together, whilst also alowing the transfer of charge and energy easily through them, and also gives them the properties of being strong, malleable, ductile, and having high melting points.
What is the definition of electronegativity
Electronegativity is the power of an atom to attract the electron density in a covalent bond towards itself.
What is the trend in electronegativity
It increases as you go up and right in the periodic table
What is polarity
When one of the atoms in a covalent bond has a greater share of the electron density, it causes that atom to be partially negative, and the other partially positive, which will act as if they were magnets
What are the three types of inter-molecular forces from weakest to strongest
Van der Waals forces - where there is momentary charge displacement causes momentary attraction between different molecules
Dipole-dipole forces - where the Molecule has overall polarity, so therefore they line up and form stronger inter-molecular bonds that normal
Hydrogen bond - a form of Dipole-dipole, where there is a hydrogen involved, causing a far stronger bond
What is electron pair repulsion theory
Each pair of electrons around an atom will repel all other pairs, causing the pairs to take up positions as far apart as possible, to minimise the repulsion
What is the bond angle is a linear molecule
180
What is the bond angle in a trigonal planar molecule
120
What is the bond angle in a tetrahedral molecule
109.5
Bond angle in trigonal bipyramidal
120 and 90
Bond angle in Octahedral
90
