Chapter 5, Electrons and Bonding Flashcards
What is an atomic orbital?
A region around the nucleus that can hold up to two electrons, with opposite spins.
What are the different types of orbitals?
s, p, d and f orbitals
s - how many orbitals and electrons
one orbital so it can hold two electrons
p - how many orbitals and electrons
has three orbitals so can hold 2*3= 6 electrons
d - how many orbitals and electrons
has 5 orbitals so can hold 2*5= 10 electrons
f - how many orbitals and electrons?
has 7 orbitals so can hold 2*7= 14 electrons
What are ionic compounds?
Oppositely charged ions held together by electrostatic attraction.
Features of giant ionic structures
regular structure
cubic shape
giant repeating pattern
Why do most ionic compounds dissolve in water?
As water molecules are polar they can attract the positive and negative ions and break up the structure.
Why do ionic compounds have high melting points?
As there are many strong electrostatic forces between oppositely charged ions. Lots of energy needed to overcome these forces.
What is covalent bonding?
The sharing of outer electrons in order for the atoms to obtain a full shell.
What is a dative covalent bond?
Where ONE atom donates 2 electrons to an atom or ion to form a bond.
Why do molecules have specific shapes?
Since bonds repel each other equally. Bonds contain electrons so they will want to be as far apart as possible.
What do lone pairs do in terms of shape?
Change the shape and bond angles. Lone pairs push bonding pairs closer together.
Carbon dioxide
BP-2 LP-0 linear 180
BCl3 (boron trichloride)
BP-3 LP-3 trigonal planar 120
CH4 (methane)
BP-0 LP-0 Tetrahedral 109.5
PCl5
BP-5 LP-0 trigonal bipyramidal 120 and 90 degrees
SF6 sulfur hexafluoride
BP-6 LP-0 octahedral 90
NH3 ammonia
BP-3 LP-1 trigonal pyramidal 107
H20 water
BP-2 LP-2 non linear 104.5
What is electronegativity?
The ability for an atom to attract electrons towards itself in a covalent bond.
How do we quantify how electronegative an element is?
By using the Pauling scale.
How can covalent bonds become polar?
If the atoms attached to it have a difference in electronegativity.
What happens in an induced dipole dipole?
Electrons in an atom or molecule can move from one end to another
Which crystal does an induced dipole-dipole force occur in?
Iodine
Why are there weaker induced dipole-dipole forces in branched hydrocarbons?
As they can’t pack together as close. This lowers their boiling points.
