Chapter; Element From The Sea Flashcards
How can relative atomic masses be found?
Mass spectrometry
Describe an absorption spectrum
Coloured background
Black lines- occurs where frequencies are missing
Describe an emission spectrum
Black background
Coloured lines- occur where frequencies are emitted
Spectroscopy is?
The study of how light and matter interact
An s- sub shell contains one how many orbitals ?
1
A p- sub shell contains how many orbitals?
3
A d- sub shell contains
5 orbitals
An f - sub shell contains
7 orbitals
Pieces of information needed when describing an electron?
- the electron shell that it’s in
- it’s sub shell
- it’s orbital within the sub shell
- It’s spin
A covalent bond?
Bonding between non-metallic elements where electrons are shared a of transferred
Lone pair?
A pair of electrons that are not involved in bonding.
Dative covalent bond?
When electrons in the bond come from one element
What is the bond angle for a molecule with 4 groups of electrons around central atom with no lone pairs? (Methane)
Tetrahedral shape
109.5
4 electron groups around central atom and one lone pair has a bond angle of? (Ammonia)
Pyramidal shape
107
4 groups of electrons around the central atom and two lone pairs? (Water)
Bent shape
104.5
Linear molecules have a bond angle of?
2 electron groups around the central atom
180
Planar molecules have a bond angle of ?
3 electron groups around central atom
120
Bipyramidal molecules have 5 groups of electrons surrounding the central atom, what is the bond angle ?
120 or 90 depending on the position
Mass =
Mr x Mols
Avogdro’s constant is
The amount of formula units or particles in one mole of a substance
Percentage yield =
Actual yield / theoretical yield multiplied by 100
Ionic bonding is
When metallic and non metallic elements transfer electrons to make cations and anions that are held together by electrostatic bonds.
Ionic compound properties
- Typically solid at room temperature
- Form in giant lattices
- High melting points
Metallic bonding is
Bonding in metals, delocalised sea of electrons hold cations together due to electrostatic attraction.
A covalent network is
Elements like carbon form large covalently bonded networks. Consisting of very strong covalent bonds between atoms.
Properties of covalent networks
- Insoluble in water
- Does not conduct electricity
- High melting point
Ionisation
When an electron has been lost
First ionisation enthalpy is
The energy needed to remove one electron from every atom in one mole of isolated gaseous atoms of the element.
An acid is
A compound that dissociates in water to produce hydrogen ions.
An base is
A compound that reacts with an acid to produce water
An alkali is
A base that dissolves in water to form hydroxide ions
What is Relative Atomic Mass ?
It is the average of relative isotopic masses, taking into account their abundances.