Chap 5 Electrons and bonding Flashcards
1
Q
How many electrons can be held in the first four shells
A
- 1-2
- 2-8
- 3-18
- 4-32
2
Q
What are shells
A
- 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
3
Q
What are atomic orbitals
A
- 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
4
Q
Describe an s orbital
A
- 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
5
Q
Describe p orbitals
A
- 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
6
Q
Descrbie the d and f orbitals
A
- each shell from the 3rd shell contains five d orbitals
- each hell from fourth shell contains seven f orbitals
7
Q
How many electrons can be held in each sub shell
A
- s-2
- p-6
- d-10
- f-14
8
Q
What the order in which the orbitals fill up
A
- 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
9
Q
Why do electron pair with opposite spins
A
- 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
10
Q
How do the electrons fill up orbitals and why
A
- 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
11
Q
What is the electron configuration of krypton
A
- 1s2,22,2p6,3s2,2p6,4s2,3d10,4p6
12
Q
What is the shorthand electronic configuration of sodium
A
- (Ne)3S1
13
Q
What are positive ions
A
- atoms lose electrons
14
Q
What are negative ions
A
- atoms gain electrons
15
Q
What are elements in the s block
A
- highest energy electrons in s sub shell
- group 1 and 2
16
Q
What are the elements in a p block
A
- group 3-8
- highest energy electron in a p sub shell
17
Q
What happens with electron configuration of ions in a d block electrons
A
- 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
18
Q
What is ionic bonding
A
- is the electrostatic attraction between positive and negative ions in all directions
- hold cations and anions in ionic compounds
19
Q
What are common cations in ionic bonding
A
- metal ions Na+,Ca2+Al3+
- ammonium ions NH4+
20
Q
What are common anions in ionic bonding
A
- non metal ions Cl-,O2-
- polyatomic ions No3-,So42-
21
Q
Decribe the electron transfer in ionic compounds
A
- 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
22
Q
What is the structure of ionic compounds
A
- giant ionic lattice
23
Q
Describe the melting and boiling points of ionic compounds
A
- 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
24
Q
Describe the solubility of ionic compounds
A
- 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
25
Describe the electrical conductivity of ionic compounds
* in a solid state ionic compound does not conduct electricity
* once metled or dissolved in water ionic compound does not conduct electricity
26
Why can't ionic compound conduct electricity in solid state
* ions are in fixed positions in giant ionic lattices
* no mobile charge carriers
27
Why can
an ionic compound conduct electricity when dissolved or molten
* solid ionic lattice break down
* ions are now free to move as movile charge carriers
28
What are properites of ionic compound
* high melting and boiling points
* dissolve in polar solvents such as water
* conduct electricity only in liquid or aqueous state
29
What is covalent bonding
* strong electrostatic attraction between a shared pair of electrons and nuclei of bonded atoms
30
Where does covalent bonding occur in
* non metallic elements
* compounds on non metallic element
* polyatomic ions
31
What are the structure of covalent bonding
* simple molecular
* giant covalent structure
* charge polyatomic ions
32
Describe orbital overlap when referring to covalent bonding
* overlap of atomic orbitals
* each containing one elctron to five a shared pair of electrons
33
How is a covalent bond localised
* attraction acting solely between shared pair of electrons and nuclei of the two bonded atoms
34
How many electrons can boron hold in its outer shell
6
35
How many electrons can phosphorus hold in it's outer shell
* 10
36
How many electrons can sulfur hold in it outer shell
12
37
How many electrons can chlorine hold in its outer shell
14
38
What is a dative covalent bond
* covalent bond in which the shared pair of electron has been supplies by one of the bonding atoms only
