Chapter 5 - Electrons and bonding Flashcards
What is the shell number/ energy level number called?
Principle quantum number
What are shells made up of?
Made up of atomic orbitals, grouped together in sub-shells.
How many electrons can an orbital hold?
Can hold up to 2 electrons, with opposite spins
What is the shape of the s-subshell?
Shape of a sphere
What is the shape of a p orbital?
Dumbell shape
How many electrons are in each subshell?
s subshell - 2 electrons (1 orbital)
p subshell - 6 electrons (3 orbitals)
d subshell - 10 electrons (5 orbitals)
f subshell - 14 electrons (7 orbitals)
What are the rules for how many orbitals are occupied by electrons?
- Orbitals fill in order of increasing energy. Each shell has increasing energy of subshells e.g. in n=2 shell, the order of filling is 2s,2p.
The exception to this is 3d overlapping with 4s. 1 electron fills in the 4s subshell before the 3d subshell fills. - One electron occupies each orbital before pairing starts. This prevents any repulsion between paired electrons until there is no further orbital available at the same energy level.
Electrons must have opposite spin when paired in orbital.
Give the electron configuration of K?
K (pottasium)
1s2 2s2 2p6 3s2 3p6 4s1
What is ionic bonding?
Electrostatic attraction between positive and negative ions, holding them together in an ionic compound.
Describe electron transfer in an ionic bond
Outer electron(s) from metal atom are transferred to outer shell of non metal atom forming cation and anion.
What is the structure of ionic compounds?
Each ion attracts oppositely charged ions in all directions forming a giant ionic lattice.
What are the properties of an ionic compound?
- High melting + boiling points due to large amount of energy required to overcome strong electrostatic forces of attraction between oppositely charged ions.
- Dissolve in polar solvents, such as water - polar molecules break down the lattice and surround ion in the solution. If relative strengths of attractions within lattice increases then the solubility will decrease.
- Conducts electricity when molten or dissolved, as ions are free to move as charge carriers.
What is covalent bonding?
Strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms.
What is a double bond?
When the electrostatic attraction is between 2 shared pair of electrons and the nuclei of the bonded atoms.
What is a dative covalent bond?
Covalent bond where the shared pair of electrons has been supplied by one of the bonding atoms only. (originally a lone pair of electrons)
