Elements of life 5 & 6 Flashcards
1
Q
what are the names for compounds with 1-4 atoms :
A
- Monatomic
- Diatomic
- Triatomic
- tetra-atomic
- penta-atomiic
2
Q
What is covalent bonding ?
A
- When non-metallic elements react is it not energetically flavourable to form ions - electrons are shared between the atoms of the elements to form compounds.
- The resulting compounds is more stable than the individual elements.
3
Q
show a compound that:
1. single bond
2. double bond
3. triple bond
A
- H-H
- O=C=O
- H-C (triple lines) N
4
Q
What is dative bonds?
A
- When both the bonding electrons come from one atom
- and can be represented by an arrow
5
Q
How are the atoms in a simle covalent bonds? and some properties
A
- There is an electrostatic attraction between the positive nuclei of the 2 atoms and the shared pair of electrons in the bond.
- elements and compounds with a simple molecular structure have relatively low melting and boiling point
- there is no charged particles, covalent simple molecules do not conduct electricity
- they mostly do not dissolve readily in water
6
Q
what is the electron pair repulsion theory usuing methane compound:
A
- In ch4 there are four groups of electrons around the central carbon atom which are bonded by four covalent bondings pairs.
- The bond angle of H-C-H are 109.5 this is because the shape of the compound is tetrahedral with the hydrogen atoms bonded around central carbon arranged themselves to minimise the repulsion
7
Q
what are the three patternes when drawing structure:
A
- Towards you = solid block and wedged-shaped lines
- bonds away = dashed wedges
8
Q
Describe the structure of BeCl2 :
A
- There are two groups of electrons around the central atom
- Angle = 180
- name = linear
9
Q
what is the structure of the BF3:
A
- There are three (single covalent bonds) groups of electron around the central atom
- Bond angle = 120
- triangular planar
10
Q
What structural are Methanal and ethane ?
A
- Planar, this is because there is three pairs of electrons around the center
11
Q
what is the structure of the NH3 ?
A
- there is 4 pairs of electron
- 3 bonding pairs
- 1 lone pairs
- angle = 107
12
Q
what is the structure of the HO2 ?
A
- Bent
- 4 electron pairs
- 2 bonding pairs
- 2 lone pairs
- 104.5 degree around
13
Q
what is the strcuture of SO2 ? o=s=o
A
- Bent
- 118 = angle
- 3 electron groupa
- 2 bonding grous
- 1 lone pair
14
Q
Give the shape and bond angle of the PCl5:
A
- Five groups of electrons around a central atom give rise to a trigonal bipyramidal shape
- 90 and 120
- 5 pairs of electrons (all binding of electrons)
15
Q
Give the shape and bond angle of the molecule SF6:
A
- Six groups of electrons around a central atom gives rise to an octahedral shape
- where the electrons are directed to six corners of an octahedron
- 90 degree around the angle
