5 Electrons and bonding Checklist

Give the number of electrons that can fill the first four shells

Describe atomic orbitals

The region around the nucleus that can hold up to two electrons with opposite spins

What is the shape of a s-orbital

Spherical

What is the shape of a p-orbital

Dumbbell shaped

rules of orbitals

• orbitals fill in order of increasing energy

• electrons pair with opposite spins

• orbitals with the same energy are occupied first

What is within a shell, and what is within that?

Within a shell, there are subshells

Within subshells there are orbitals

What is the electron configuration of Hydrogen

1s¹

What is the electron configuration of Helium

1s²

What is the electron configuration of Neon

1s²2s²2p⁶

^{Total number of electrons is 10}

What is the electron configuration of Argon

1s²2s²2p⁶3s² 3p⁶

Total number of electrons is 18

How many electrons can the second shell hold up to?

8 electrons

2s2, 2p6

How many orbitals in the second shell

4 orbitals

1 s-orbital, 3 p-orbitals

How many electrons can the third shell hold up to

18 electrons

3s2, 3p6, 3d10

How many orbitals in the third shell

9 orbitals

1 s-orbital, 3 p-orbitals, 5 d-orbitals

How many electrons can the fourth shell hold up to

32

4s2, 4p6, 4d10, 4f14

How many orbitals in the fourth shell

16 orbitals

1 s-orbital, 3 p-orbitals, 5 d-orbitals, 7 f-orbitals

Why do some subshells overlap

The further from the nucleus, the closer together the energy levels become

When using the periodic table for electronic configuration, what does the period show?

what number the highest energy subshell will be

e.g. in the 3rd period of the p-block, it will be a 3p subshell

When using the periodic table for electronic configuration, what does the column of the block show?

how many electrons in the highest energy subshell

e.g. in the 5th column of the p-block, p^5

def ionic bonding

the strong electrostatic attraction between positive and negative ions

def isoelectronic

to have the same electronic configuration as a noble gas when ions form

def ionic lattice

in an ionic compound, millions of ions are packed together in a regular cubic arrangement, joined by ionic bonds. this forms a giant 3d structure called an ionic lattice

the ionic lattice will continue to build this way until there are no more ions left to add

the structure of the ionic lattice affects the properties of the ionic compound

what 2 processes does solubility require in ionic substances

the ionic lattice must be broken down

water molecules must attract and surround the ions

what does the solubility of an ionic compound in water depend on

charge and size - bigger ions have more electron shielding so nuclear attraction is less

the relative strength of the attractions within the giant ionic lattice of the attraction between ions and the attractions between ions and water molecules

solubility decreases as ionic charge increases

with ionic compounds that have large ionic charges the attraction in the giant ionic lattice have a greater effect than the attraction of the polar water molecules

when is something soluble

if the energy released upon hydration is the same as the energy required to break the giant ionic lattice

def dissolve

when water molecules surround small components of what was put in the water

why are ionic compounds soluble in water

because of their charge. water is a polar solvent and the polar water molecules break down the lattice and surround each ion in solution

when is something dissolved

when the ion is surrounded in solution/ solvated

what is the structure of an ionic compound

crystalline because of the regular cubic shaped giant ionic lattice

why are ionic compounds brittle

because of their giant ionic lattice, if one layer is shifted then like ions will be over each other therefore that layer will be repelled

what is a coordination number

the number of oppositely charged ions that can surround the ion in the middle

shown in a ratio e.g. Na has a coordination no. of 6:6

def covalent bond

an electrostatic attraction between a pair of shared valence electrons and the nuclei of the atoms

or

the overlap of atomic orbitals, each containing one electron, to give a shared pair of electrons

difference between covalent vs ionic bonds

covalent:

• attraction is localised, activity is solely between the shared pair of electrons and the nuclei of the two bonded atoms

• covalent substances can exist as molecules

what is the octet rule

all atoms in a molecule have to have 8 valence electrons to become stable. in a covalent bond, atoms share their electrons with each other to satisfy the octet rule

(There are exceptions)

What is the strength of a covalent bond

the strength of a covalent bond is shown by its average bond enthalpy (measures the energy required to break a covalent bond). The stronger a bond is, the more energy is required to break it, and so the greater the value of the average bond enthalpy

def dative covalent bond

a covalent bond in which the shared pair of electrons has been supplied by one of the bonding atoms only. in a dative covalent bond the shared electron pair was originally a lone pair of electrons on one of the bonded atoms.

e.g. a when an ammonia molecule donates its lone pair of electrons to a H+ ion (H+ ions has no electrons)

electron configuration for chromium Cr

1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s¹

electron configuration for copper Cu

1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹ 3d¹⁰

subshell triangle thing