Chemistry A-Level
pencil baseline
What pencil baseline means in Chemistry A-Level, as defined for AQA.
Definition of pencil baseline
Check what you remember
Read the wording for your board, then hide it and explain pencil baseline in your own words. Rough notes are fine. This is a self-check, with no mark or grade.
Reference: AQA
A line ruled in pencil about a centimetre from the bottom of the plate, because ink would dissolve and travel with the solvent.
Topics that use pencil baseline
- Chromatography (A-level only) (AQA A-Level)
Related terms
- adsorption
- fragmentation fingerprint
- gas chromatography
- gas chromatography with mass spectrometry
- lid and saturated vapour
- molecular ion peak
- retention time
- Rf value
Using pencil baseline in the exam
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