Electrons And Bonding

Question 1

Shell number/energy level

Answer 1

Principle quantum number

Question 2

Atomic orbital

Answer 2

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

Question 3

Subshell

Answer 3

Groups of orbitals

Question 4

Opposite spins

Answer 4

Help counteract the repulsion between negative charges of e-

Question 5

4s sub shell

Answer 5

Fills and empties before 3D as once filled the 3D falls below the 4s subshell

Question 6

Ionic bonding

Answer 6

Electrostatic attraction between positive and negative ions

Question 7

Ionic melting and boiling points

Answer 7

High temperatures needed to provide the energy to overcome the strong electrostatic attraction between the ions ionic compounds have high melting and boiling points Higher ionic charge increases boiling point as stronger attraction between ions

Question 8

Solubility of ionic compounds

Answer 8

Most dissolve in polar solvents such as water polar molecules break down the lattice and surround each ion in solution.
Large charges may be too strong for water to be able to break down the lattice structure the water will then not dissolve

Question 9

Two processes for solubility

Answer 9

Ionic lattice must be broken down and water molecules must attract and surround the ions

Question 10

Ionic electrical conductivity

Answer 10

Does not conduct as a solid but once melted or aqueous electrons are free to move and carry charge

Question 11

Covalent bonding

Answer 11

The strong electrostatic attraction between A shared pair of electrons and the nuclei of the bonded atoms occurs between non-metal elements orbital overlap

Question 12

Molecule definition

Answer 12

The smallest part of a covalent compounds that can exist whilst retaining the chemical properties of the compound

Question 13

Boron bonding

Answer 13

Has three outer shells that can be pad forms three covalent bonds only six electrons in outer shell

Question 14

Expanding the octet

Answer 14

From n=3

In sulphur phosphorus and chlorine depending on the number of unpaired electrons depends on how many bonds can form

Question 15

Average bond enthalpy

Answer 15

A measurement of covalent bond strength the larger the value the stronger the bond. Always endothermic BENDO

Question 16

Ammonia shaped

Answer 16

Pyramidal 107°

Question 17

Water shape

Answer 17

Non linear

104.5

Question 18

Electronegativity

Answer 18

The attraction of a bonded atoms for the pair of electrons in a covalent bond.

Question 19

Dipole

Answer 19

Separation of opposite charges

Question 20

Dipoles from polar bonds

Answer 20

Permanent dipoles- do not change

Question 21

Intermolecular forces

Answer 21

Weak interactions between dipoles of different molecules

Responsible for the physical properties of the compound

Question 22

London forces

Answer 22

Induced dipole dipole interactions

Question 23

Three types of intermolecular forces

Answer 23

London forces weakest

permanent dipole interaction hydrogen bonding strongest

Question 24

London forces working

Answer 24

Movement of electrons produces the changing dipole in a molecule
And instantaneous dipole will exist but its position is constantly shifting the instantaneous dipole induces a dipole on a neighbouring molecule
Temporary- the next instance dipole disappears

Question 25

Strength on induced dipole interactions

Answer 25

Larger dipole- greater interaction Stringer attractive forges More electrons= larger induced dipoles=more energy needed to overcome

Question 26

Permanent dipole interactions

Answer 26

Act between the permanent dipoles in different molecules

Question 27

Simple molecular substances

Answer 27

Made up of simple molecules small units containing a definite number of atoms with a definite molecular formula in the solid-state form a simple molecular lattice where the molecules are held in place by weak intermolecular forces but the atoms within each molecule are bonded together strongly by covalent bonds

Question 28

Melting points and boiling point a simple molecular substances

Answer 28

Low melting and boiling point as molecular forces are weak so easy to overcome but covalent bonds are strong and do not break

Question 29

Simple molecular substances solubility

Answer 29

Can be polar or nonpolar nonpolar dissolve in nonpolar substances such as hexane when intermolecular forces be formed between the molecules and a solvent do not dissolve in polar solvents as intermolecular bonds within the solvent are too strong Polar simple molecular substances may dissolve in polar- depends on strength of dipole. Some C chains too long C2H5OH dissolve in polar and non polar

Question 30

Hydrogen bonds

Answer 30

Special type of permanent dipole interaction between molecules containing and electronegative atom with a lone pair (O N F) and a hydrogen attached to electronegative atom acts between lp and H strongest IM force

Question 31

Anomalous properties of water

Answer 31

Solid is less dense than the liquid water has high melting points and boiling point and high surface tension

Question 32

Ice vs water

Answer 32

Hydrogen bonds hold water molecules are part in an open lattice structure water molecules in ice a further apart then in water solid ice is less dense than water and floats

Question 33

Water melting points and boiling point

Answer 33

Hydrogen bonds are extra forces lots of energy needed to break the bonds water has a high melting and boiling points when water boils a hydrogen bonds are broken completely