AQA A Level Physics复习笔记1.2.2 Calculating Uncertainties
Uncertainty There is always a degree of uncertainty when measurements are taken; the uncertainty can be thought of as the difference between the actual reading taken (caused by the equipment...
AQA A Level Physics复习笔记1.1.3 Estimating Physical Quantities
Orders of Magnitude A quantity is an “order of magnitude” larger than another quantity if it is about ten times larger Similarly, two orders of magnitude would be 100 times larger, or 102 &n...
AQA A Level Physics复习笔记1.1.2 Powers of Ten
Powers of Ten Physical quantities can span a huge range of values For example, the diameter of an atom is about 10–10 m (0.0000000001 m), whereas the width of a galaxy may be about 1021 m (1...
AQA A Level Chemistry复习笔记8.3.4 Required Practical 12
Separation of species by TLC Required practical 12: Separation of species by thin-layer chromatography This practical covers two key laboratory skills use thin-layer or paper chromatography safely ...
AQA A Level Chemistry复习笔记8.3.3 Testing Aldehydes & Ketones
Tollens' Reagent Testing Distinguishing Between Aldehydes & Ketones Weak oxidising agents can be used to distinguish between an aldehyde and a ketone The aldehyde will be oxidised to a c...
AQA A Level Chemistry复习笔记8.3.2 Required Practical 10b
Preparation of an Ester This required practical covers the following mandatory skills use water bath or electric heater or sand bath for heating use laboratory apparatus for a variety of exp...
AQA A Level Chemistry复习笔记8.2.9 Reactions of Metal-Aqua Ions
Reactions of Metal-Aqua Ions In this practical activity, test tube reactions of copper(II), iron(II), iron(III) and aluminium ions with three bases are investigated 10 drops of the metal-aqu...
AQA A Level Chemistry复习笔记8.2.8 Identifying Ions
Identifying Ions Testing for positive ions Simple test tube reactions can be done to identify the following positive ions: Group 2 ions (M2+) Ammonium ions (NH4+) If the sample to be ...
AQA A Level Chemistry复习笔记8.2.7 Autocatalysis Experiments
Autocatalysis Experiments Autocatalysis Experiment - Titration with sodium thiosulfate Autocatalysis occurs when one of the products catalyses the reaction Potassium manganate(VII) will reac...
