Chap 5 Electrons and bonding

Question 1

How many electrons can be held in the first four shells

Answer 1

• 1-2
• 2-8
• 3-18
• 4-32

Question 2

What are shells

Answer 2

• regarded as eergy levels whcih hold electrons
• energy increases as shell number increases
• shell number of energy level number is alled the principal quantum number

Question 3

What are atomic orbitals

Answer 3

• shells are made of atomic orbitals
• regions around the nucleus that can hold up to 2 electrons with opposite spins
• there are different types s,p,d,f
• each type of orbital has a different shape

Question 4

Describe an s orbital

Answer 4

• electron cloud within the shape of a sphere
• can hold up to 1 or two electrons
• each shell contain one s orbital
• greater shell number the greater the radiu of its s orbital

Question 5

Describe p orbitals

Answer 5

• electron cloud with the shape of a dumb bell
• one orbital can contain one to two electrons
• three seperate p orbitals
• each shell from the second shell contains 3 p orbitals
• greater the shell number the further the p orbital is from

Question 6

Descrbie the d and f orbitals

Answer 6

• each shell from the 3rd shell contains five d orbitals
• each hell from fourth shell contains seven f orbitals

Question 7

How many electrons can be held in each sub shell

Answer 7

• s-2
• p-6
• d-10
• f-14

Question 8

What the order in which the orbitals fill up

Answer 8

• 1s, 2s ,2p,3s,3p,4s,3d,4p
• 3d sub shell has a higher energy level than the 4s sub shell
• 4s sub shell therfore fills before the 3d sub shell

Question 9

Why do electron pair with opposite spins

Answer 9

• each orbital can hold up to two electrons
• electrons are negativley charged and repel on another
• electrons can spin either up or down
  the electrons in an orbital must have opposite spins which help counteract the repulsion between the negative charges of the two electrons

Question 10

How do the electrons fill up orbitals and why

Answer 10

• within a sub shell obritals have same energy and electrons occupy orbitals singally befoe they pair up
• prvents any repulsdion between paired electrons until no further orbital available with same energy

Question 11

What is the electron configuration of krypton

Answer 11

• 1s2,22,2p6,3s2,2p6,4s2,3d10,4p6

Question 12

What is the shorthand electronic configuration of sodium

Answer 12

• (Ne)3S1

Question 13

What are positive ions

Answer 13

• atoms lose electrons

Question 14

What are negative ions

Answer 14

• atoms gain electrons

Question 15

What are elements in the s block

Answer 15

• highest energy electrons in s sub shell
• group 1 and 2

Question 16

What are the elements in a p block

Answer 16

• group 3-8
• highest energy electron in a p sub shell

Question 17

What happens with electron configuration of ions in a d block electrons

Answer 17

• 4s sub shell is at a lower energy than the 3d sub shell so is filled first
• energies of 4s and 3d sub shellss are very close together and once fills 3d energy level alls below 4s energy level
• 4s fills before 3d sub shell
• 4s sub shell empties before 3d sub shell

Question 18

What is ionic bonding

Answer 18

• is the electrostatic attraction between positive and negative ions in all directions
• hold cations and anions in ionic compounds

Question 19

What are common cations in ionic bonding

Answer 19

• metal ions Na+,Ca2+Al3+
• ammonium ions NH4+

Question 20

What are common anions in ionic bonding

Answer 20

• non metal ions Cl-,O2-
• polyatomic ions No3-,So42-

Question 21

Decribe the electron transfer in ionic compounds

Answer 21

• outer shell electrons from a metal atom are transferred to the outer shell of a non metal atom
• positive and negativ ions are formed
• ions formed often habve outer shells with same electron configuration as the nearest noble gas

Question 22

What is the structure of ionic compounds

Answer 22

• giant ionic lattice

Question 23

Describe the melting and boiling points of ionic compounds

Answer 23

• high melting and boiling point
• high temperatures are needed to provide a large quantity of energy to overcome the strong electrostatic attraction between the ons
• melting poitns are larger for lattices containing ions with greater ionic charges as stronger attraction between ions

Question 24

Describe the solubility of ionic compounds

Answer 24

• dissolve in polar solvents such a water
• polar water molecules break down the lattice and surround each ion in solution
• if ions have large cjarges ionic attraction mau ne too strong for water to be able to break down the lattic structure so it will not be very soluble

Question 25

Describe the electrical conductivity of ionic compounds

Answer 25

• in a solid state ionic compound does not conduct electricity
• once metled or dissolved in water ionic compound does not conduct electricity

Question 26

Why can’t ionic compound conduct electricity in solid state

Answer 26

• ions are in fixed positions in giant ionic lattices
• no mobile charge carriers

Question 27

Why can
an ionic compound conduct electricity when dissolved or molten

Answer 27

• solid ionic lattice break down
• ions are now free to move as movile charge carriers

Question 28

What are properites of ionic compound

Answer 28

• high melting and boiling points
• dissolve in polar solvents such as water
• conduct electricity only in liquid or aqueous state

Question 29

What is covalent bonding

Answer 29

• strong electrostatic attraction between a shared pair of electrons and nuclei of bonded atoms

Question 30

Where does covalent bonding occur in

Answer 30

• non metallic elements
• compounds on non metallic element
• polyatomic ions

Question 31

What are the structure of covalent bonding

Answer 31

• simple molecular
• giant covalent structure
• charge polyatomic ions

Question 32

Describe orbital overlap when referring to covalent bonding

Answer 32

• overlap of atomic orbitals
• each containing one elctron to five a shared pair of electrons

Question 33

How is a covalent bond localised

Answer 33

• attraction acting solely between shared pair of electrons and nuclei of the two bonded atoms

Question 34

How many electrons can boron hold in its outer shell

Answer 34

6

Question 35

How many electrons can phosphorus hold in it’s outer shell

Answer 35

• 10

Question 36

How many electrons can sulfur hold in it outer shell

Answer 36

12

Question 37

How many electrons can chlorine hold in its outer shell

Answer 37

14

Question 38

What is a dative covalent bond

Answer 38

• covalent bond in which the shared pair of electron has been supplies by one of the bonding atoms only