2022 ISSCY联合国高中人文社科写作比赛报名8月底截止，附参赛时间及比赛规则
由世界联合国协会主办的写作学术活动 所有涵盖人文社科的相关领域 全球仅80篇优秀论文发表 2022ISSCY联合国高中人文社科写作比赛 截稿在即！ 截止日期：美国东部时间2022年8月24日23:59 ISSCY联合国高中人文社...
CIE A Level Chemistry复习笔记2.3.2 Chemical Properties: Halogens & Hydrogen Halides
Group 17: Oxidising Agents Halogens react with metals by accepting an electron from the metal atom to become an ion with 1- charge Eg. Ca(s) + Cl2(g) → Ca2+(Cl-)2(s) Halogens are therefore oxidis...
CIE A Level Chemistry复习笔记2.3.1 Physical Properties of the Group 17 Elements
Group 17: Physical Trends The group 17 elements are called halogens The halogens have uses in water purification and as bleaches agents (chlorine), as flame-retardants and fire extinguishers (bromi...
ISSCY联合国高中人文社科写作比赛获奖作品赏析，附ISSCY写作策略
ISSCY联合国高中人文社科写作比赛是一个面向全世界高中生的研究学术活动，由联合国协会世界联合会（WFUNA）、美国青年会（YOUTHECA USA）等其他全球非政府组织共同主办和赞助的，作为高度竞争的活动项目，此学术...
CIE A Level Chemistry复习笔记2.2.5 Group 2: Trends in Solubility of Hydroxides & Sulfates
Trends in Solubility in Group 2 Hydroxides & Sulfates Group 2 hydroxides Going down the group, the solutions formed from the reaction of Group 2 oxides with water become more alkaline When the ...
CIE A Level Chemistry复习笔记2.2.4 Group 2: Physical & Chemical Trends
Group 2: Physical & Chemical Trends Chemical trends All elements in Group 2 (also called alkali earth metals) have the two electrons in their outermost principal quantum shell All Group 2 metal...
CIE A Level Chemistry复习笔记2.2.3 Thermal Decomposition of Nitrates & Carbonates
Group 2: Thermal Decomposition of Nitrates & Carbonates Thermal decomposition is the breakdown of a compound into two or more different substances using heat Thermal decomposition of carbonates...
CIE A Level Chemistry复习笔记2.2.2 Reactions of Group 2 Oxides, Hydroxides & Carbonates
Reactions of Group 2 Oxides, Hydroxides & Carbonates Reactions of Group 2 oxides with water All Group 2 oxides are basic, except for BeO which is amphoteric (it can act both as an acid and base...
CIE A Level Chemistry复习笔记2.2.1 Reactions of Group 2 Elements
Reactions of Group 2 Elements The Group 2 elements react with oxygen, water and dilute acids Group 2 reactions table Group 2 reactions with oxygen & water chemical equations Group 2 reactions w...
CIE A Level Chemistry复习笔记2.1.8 Chemical Periodicity of Other Elements
Periodicity: Predicting Position & Properties If the chemical and physical properties of an element are known, the position of that element in the Periodic Table can be predicted Similarly, pre...
CIE A Level Chemistry复习笔记2.1.7 Period 3 Chlorides & Oxides
Bonding in Period 3 Chlorides & Oxides Period 3 chlorides The bonding and structure of the Period 3 elements are summarised in the table below: The table shows that Na, Mg and Al are metallic e...
CIE A Level Chemistry复习笔记2.1.6 Period 3 Elements: Electronegativity & Bonding
Period 3: Trends in Electronegativity & Bonding Electronegativity Electronegativity is the power of an element to draw the electrons towards itself in a covalent bond Going across the period, t...
