Chapter 5- Electrons and Bonding

what is the maximum number of electrons that can fill the first four shells?

2, 8, 18, 32

what is an atomic orbital?

a region around the nucleus that can hold up to 2 electrons with opposite spins

what are the different types of orbitals?

• s

• p

• d

• f

how many electrons can an s-subshell hold?

2 electrons

how many electrons can a p-subshell hold?

6 electrons

how many electrons can a d-subshell hold?

10 electrons

shape of the different orbitals?

• s orbital- spherical (one occurs in every principal energy level)

• p orbital- dumb bell ( 3 ocur in energy levels except the first)

• d orbital- various ( 5 occur in energy levels except the first and second)

• f orbital- various 

how does the energy of the orbitals increase?

it increases from s to p to d

• meaning the orbitals are filled in this order

what are the three rules for writing out electron configurations?

• the lowest energy orbital is filled first

• for orbitals with the same energy, electrons occupy orbitals singly with the same spin before pairing begins

• no single orbital holds more than 2 electrons

within an orbital, how do electrons pair up?

they pair up with the opposite spin so that the atom is as stable as possible

• electrons in the same orbital must have opposite spins

• the spins are represented by opposite arrows

number of orbitals that s,p and d subshells contain?

• s subshell- 1 orbital

• p subshell- 3 orbitals

• d subshell- 5 orbitals

order of orbitals?

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 4d, 4f

what is ionic bonding?

the electrostatic attraction between positive and negative ions

how is a giant ionic lattice formed?

oppositely charged ions attract each other through electrostatic forces to form a giant ionic lattice

what is the relationship between charge of ion and strength of ionic bond formed?

• ions with a greater charge will have a greater attraction to the other ions, resulting in stronger forces of attraction and therefore, stronger ionic bonding

do larger ions with a greater ionic radius have a weaker or stronger attraction to the oppositely charged ion?

weaker attraction because the attractive forces have to act over a greater distance

phsycial properties of ionic compounds?

• high melting and boiling points because the electrostatic forces holding the ionic lattice together are strong and require a lot of energy to overcome

• only conduct electricity in molten or aqueous solution because the ions separate and are no longer held in a lattice. the ions are free to move and carry a flow of charge

• they are brittle materials- when the layers of alternating charges are distorted, like charges repel, breaking apart the lattice into fragments

• tend to dissolve in polar solvents such as water

why do ionic compounds dissolve in polar solvents such as water?

• the polar water molecules break down the lattice and surround each ion in solution

• however, in a compound made of ions with large charges, the ionic attraction may be too strong for water to be able to break down the lattice structure

• this causes the compound to not be very soluble

what two main processes does solubility require?

• the ionic lattice must be broken down

• water molecule must attract and surround the ions

what is covalent bonding?

the electrostatic attraction between a shared pair of electrons and 2 positive nuclei.

• a covalent bond is the overlap of atomic orbitals, each containing one electron, to give a shared 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.

• example of this is NH4

what is average bond enthalpy?

a measurement of covalent bond strength

• the larger the value of the average bond enthalpy, the stronger the covalent bond

compare the bond enthalpies of single and triple covalent bonds?

• single covalent bonds involve less shared electrons, and therefore have a weaker electrostatic attraction between the nuclei, as to why they have the weakest bond

why are triple bonds shorter than single bonds?

• they have a greater number of shared electrons, meaning greater electrostatic pull between nuclei. this stronger pull causes nuclei to come closer together, making the bond shorter, but stronger