第744页-翰林严选-翰林国际教育

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翰林严选

2020年丘奖物理金奖作品解析

2022-09-21

作为提交截止时间最晚的赛区，丘奖内地赛区的论文提交即将截止，剩余时间不足一周！作为由数学大师丘成桐先生亲自发起设立的中学生科学创新类奖项，丘奖从十四年前单一的数学奖，发展到今天的数学奖、物理奖、化...

Edexcel A Level Chemistry:复习笔记6.3.4 Ligand Exchange

2022-09-21

Ligand Exchange Ligand exchange (or ligand substitution) is when one ligand in a complex is replaced by another Ligand exchange forms a new complex that is more stable than the original one ...

Edexcel A Level Chemistry:复习笔记6.3.3 Reactions of Ions in Aqueous Solution

2022-09-21

Reactions with Hydroxide & Ammonia When transition metal ions in aqueous solution react with aqueous sodium hydroxide and aqueous ammonia they form precipitates However some of these pre...

Edexcel A Level Chemistry:复习笔记6.3.2 Chromium

2022-09-21

Reduction & Oxidation of Chromium Species For chromium we need to consider the following standard electrode potential values We will use zinc and hydrogen peroxide as oxidising agents Th...

Edexcel A Level Chemistry:复习笔记6.3.1 Vanadium

2022-09-21

Colours & Oxidation States Vanadium is a transition metal which has variable oxidation states The table below shows the important ones you need to be aware of Addition of zinc to the van...

Edexcel A Level Chemistry:复习笔记6.2.12 Autocatalysis

2022-09-21

Manganese(II) ions as an Autocatalyst Autocatalysis the term used to describe a reaction which is speeded up by a product which acts as a catalyst for the reaction If you plot a rate graph o...

Edexcel A Level Chemistry:复习笔记6.2.11 Homogeneous Catalysis

2022-09-21

Homogeneous Catalysts Homogeneous catalyst is in the same physical state (phase) as the reactants This means they are either all gases, or more often, all in aqueous solution Homogenous cata...

Edexcel A Level Chemistry:复习笔记6.2.10 Heterogeneous Catalysis

2022-09-21

Heterogeneous Catalysts A heterogeneous catalyst is in a different physical state (phase) from the reactants Heterogeneous catalysts are usually solids whereas the reactants are gaseous or i...

Edexcel A Level Chemistry:复习笔记6.2.9 Catalysis

2022-09-21

Properties of Catalysts Transition metals are often used as catalysts in the elemental form or as compounds The ability of transition metals to form more than one stable oxidation state mean...

Edexcel A Level Chemistry:复习笔记6.2.8 Haemoglobin

2022-09-21

Haemoglobin Haemoglobin is one of nature's complexes using a transition metal ion The haem molecule is a complex with iron(II) at its centre The haemoglobin complex contains a multidentate l...