Electron Configuration and Experimental skills Flashcards
What is a systematic error
A recurring error which is inherent in the apparatus or experimental method used. Repeating the procedure and averaging results doesn’t eliminate random errors
3 ways to reduce systematic error
Re-calibrate instrument, change apparatus or procedure, use new standards
What are random errors
Chance variations between successive Measurements.
Random errors are indicated by ‘…’ In the measure values
Scatter
How to reduce the effect of random errors
Taking the average of repeated measurements or drawing a ‘line of best fit’ through the plotted points on a graph
The precision of a series of measurements is indicated by the degree of uniformity - the more ‘…’ The less precise
Scatter
A measurement is ‘…’ to the extent that random errors have been minimised
Precise
A measurement is ‘…’ To the extent that systematic errors have been minimised
Accurate
What is the formula for K, L, M and N
2n^2
How many electrons can K, L, M and N
2, 8, 18, 32
What can an orbital be visualised as
A blurry cloud of negative charge: the charge is most dense where the probability of finding the electron is the largest
How many orbitals and electrons does the S subshell contain
1 orbital - 2 electrons
How many orbitals and electrons does the subshell p contain
3 orbitals - 6 electrons
How many orbitals and electrons does the subshell d hold
Orbitals 5, Electrons 10
How many orbitals and electrons does the subshell f hold
Orbitals 7, Electrons 14
What is Hund’s Rule
When electrons occupy orbitals of equal energy, one electron enters each orbital until all orbitals contain one electron
What two elements do not follow the usual pattern
Chromium, Copper
What are the last two subshells of chromium
3d^5, 4s^1
What are the last two subshells of copper
3d^10 4s^1
Which electrons should be deleted first and second to create ion subshell notation
4s and 3D
How to figure out the group and period using subshell configuration
Period = number of occupied electron shells Group = number of electrons in the valence shell (Roman numerals)
Define Energy sequence of orbitals
Electrons enter orbitals of lowest energy first
define Pauli Exclusion Principal
Orbitals can only accommodate a maximum of 2 electrons, and these must have opposite spins
Metals ‘…’ Electrons in chemical reactions
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