Chapter 5 - Electrons and bonding Flashcards
What is the principle quantum number, n?
The shell number/energy level
What is an atomic orbital?
A region around the nucleus that can hold up to two electrons with opposite spins
What are the four different types of atomic orbital?
s, p, d, f
What is the shape of an s orbital, and how many does each shell contain?
Shaped like a sphere, each shell from n = 1 contains one s orbital
What is the shape of a p orbital and how many does each shell contain?
Shaped like a dumb bell, each shell from n = 2 contains three p orbitals
How many d orbitals does each shell contain?
Each shell from n = 3 contains five d orbitals
How many f orbitals does each shell contain?
Each shell from n = 4 contains seven f orbitals
How do orbitals fill?
Orbitals fill in order of increasing energy
How do electrons pair in an orbital?
One electron occupies each orbital before pairing starts, preventing any repulsion between paired electrons until there is no further orbital available at the same energy level
Why does the 4s orbital fill before the 3d orbital?
Because 3d is at a higher energy level than the 4s sub shell, so the 4s sub shell will fill first
What is ionic bonding?
The electrostatic attraction between positive and negative ions
What structure do ionic compounds form?
Giant ionic lattice
What is a giant ionic lattice?
A repeating pattern of oppositely charged ions
Why do most ionic compounds have high melting and boiling points?
There are strong electrostatic forces of attraction between the oppositely charged ions in the giant ionic lattice, high temperatures are needed to provide the large amounts of energy needed to overcome this attraction
Why do most ionic compounds dissolve in water?
The polar nature of solvents such as water break down the lattice, and attract and surround each ion in solution
Why do ionic compounds only conduct electricity when molten or in solution?
In the solid state, the ions are in a fixed position and there is no way to carry charge. Whereas in a molten state, the ionic lattice is broken and the ions are free to move and carry charge
What is covalent bonding?
The strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms
What happens to atomic orbitals in covalent bonds?
They overlap, giving a pair of shared electrons
What is a multiple covalent bond?
When two atoms share more than one pair of electrons
What is a dative covalent bond?
A covalent bond in which the shared pair of electrons has been supplied by one of the bonding atoms only (was originally a lone pair)
Why can the non-metals in Period 3 form different numbers of covalent bonds?
The n = 3 outer shell can hold 18 electrons so more electrons are available for bonding, and there are different electron pairing arrangements
What is average bond enthalpy?
A measurement of covalent bond strength
