2A The atoms and redox Flashcards
Atomic number
No. protons in the nucleus of an atom
Mass number
No. protons and. neutrons in the nucleus of an atom
Ion
Charged particle
Isotope
An atom of the same element with the same number protons and electrons, however a different number of neutrons with the same properties.
Relative isotopic mass
The mass of an atom of an isotope compared with 1/12 th of the mass of one carbon-12 atom
Why carbon-12
Exactly 12 amu and is pure + unreactive
Relative atomic mass
weighted mean mass of an atom of an element compared with 1/12 th of the mass of one carbon-12 atom
How to calculate relative atomic mass
[abundance x mass] + [abundance x mass] +[abu…] divided by the total abundance
How to work out relative abundance on a mass spectograph
[total height (cm) ÷ No. isotopes] x 100
Relative molecular mass
the weighted mean mass of a molecule compared with 1/12th of one atom of carbon-12
Relative formula mass
the weighted mean mass of a formula unit compared with 1/12th of one atom of carbon-12
1st ionisation energy
The amount of energy required to remove 1 electron from each atomic one mole of gaseous. atoms to form 1+ ions
Potassium: K(g) —-> K+(g) + e-
3 factors which effect 1st ionisation energy
- No. protons (Atomic number)
- The number of inner shells (Shielding)
- Distance from the nucleus to the outer shell
always talk about the nuclear. attraction.
Successive ionisation energy
finish.
s orbital
2 electrons
p orbital
6 electrons
d orbital
10 electrons
f orbital
14 electrons
sub shell fill order
1s2s2p3s3p4s3d4p4d4f
Most energy orbital
Least energy orbital
f block
d block
p block
s block
Which way are electrons lost?
Electrons are lost from the outer orbital regardless of energy level
Gr 1and Gr 2 and He orbital block
s block
Gr 3-8 orbital block
p block
transition metals not in G3-7 orbital block
d block
Random bottom one orbital block
f block
Exception to sub shell fill order
Copper : 1s^2 2s^2 2p^6 3s^2 3p^6 3d^10 4s^1
Chromium: 1s^2 2s^2 2p^6 3s^2 3p^6 3d^5 4s^1
Oxidation
The loss of electrons
Reduction
The gain of electrons
Oxidising agent
Removes electrons from other substances
Reducing agent
Adds electrons to other substances
Oxidation rules
- Uncombined atoms have an ON of 0
- Gr.1 elements have an ON of 1+
- Gr.2 elements have an ON of 2+
- Flourine has an ON of 1-
- Oxygen has an ON of 2-, except in peroxides its 1-
- Hydrogen has an ON of 1+ except in hydrides its 1-
Oxidation in redox
If the oxidation number is increased, oxidation has taken place
Reduction in redox
If the oxidation number is decreased, reduction has taken place
mnumonic for learnign fill order
special
performance
during
finale
