最新!2023 U.S.News全美综合大学排名榜单出炉
世界权威排名机构之一 U.S. News 官方正式发布了最新的2023年美国大学排名(2023 Best College Rankings)。U.S.News一直都是业界关注度高、认可度高、极具权威性和公信力的排行榜,原因就是它的评估标准严谨,采...
世界权威排名机构之一 U.S. News 官方正式发布了最新的2023年美国大学排名(2023 Best College Rankings)。U.S.News一直都是业界关注度高、认可度高、极具权威性和公信力的排行榜,原因就是它的评估标准严谨,采...
在世界范围内拥有广泛影响力,众多海外知名大学皆认可,这就是FBLA未来商业领袖挑战,美国高中影响力巨大的商科赛事,FBLA美国未来商业领袖峰会强推!想要攻坚名校的同学不能不知道! FBLA ( Future Business Lea...
Halide Ion Reactions Concentrated sulfuric acid Chloride, bromide and iodide ions react with concentrated sulfuric acid to produce toxic gases These reactions should therefore be carried out...
Halogen Redox Reactions Reactions with Group 1 & 2 metals The halogens react with some metals to form ionic compounds which are metal halide salts In all reactions where halogens are rea...
Halogen Displacement Reactions The reactivity of halogens is also shown by their displacement reactions with other halide ions in solutions A more reactive halogen can displace a less reacti...
Physical Properties The Group 7 elements are called halogens The halogens have uses in water purification and as bleaching agents (chlorine), as flame-retardants and fire extinguishers (brom...
Flame Tests Metal ions produce a colour if heated strongly in a flame Ions from different metals produce different colours The flame test is thus used to identify metal ions by the colour of...
Group 2 Carbonates & Nitrates Thermal decomposition is the breakdown of a compound into two or more different substances using heat Thermal decomposition of carbonates The Group 2 carbon...
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 oxides are dissol...
CTB 全球创新研究大挑战来啦!关注PBL赛事的家长和同学,CTB这个赛事对大家应该并不陌生。China Thinks Big(简称CTB),由哈佛商学院和清华大学经管学院学者联合启动,是以学术研究和社会实践推动社会创新的国际...
Group 2 Elements Reactions with water and oxygen The reaction of group 2 metals with oxygen follows the following general equation: 2M (s) + O2 (g) → 2MO (s) Where M is any metal in group 2 ...
Ionisation Energy Chemical trends All elements in Group 2 (also called alkali earth metals) have two electrons in their outermost principal quantum shell All Group 2 metals can form ionic co...
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