氢元素概念发展史与化学思想的演进

18世纪,发现氢气的卡文迪什认为该气体是水与燃素的化合物;但发现水的组成的拉瓦锡认为氢气是一种元素物质.到19世纪,原子分子论形成后,氢气被认为是由双原子分子构成的单质.20世纪30年代,氢同位素的发现使人们对氢元素概念有了新认识,并逐渐形成现代氢元素概念.氢元素概念的发展史不仅是元素概念的发展史,也是科学思想的演进史...     

锆元素概念的形成和发展

1789年,普鲁士分析化学家克拉普罗特提出黄锆石中含有一种新土质,并将其命名为“锆土”,锆元素假说正式形成。随后,锆的原子重量的测定以及锆元素在元素表中位置的确定,促进了锆元素假说的发展。1914年,荷兰工程师勒利和汉布格首次制得纯度较高的金属锆,这使得锆元素假说得以证实,锆元素概念正式形成。从1924年至2020年,锆同位素的发现使人们对锆元素有了新认识,促使了现代锆元素概念的形成。锆元素概念的形成和发展的过程既是元素的发现史,也是化学思想和化学方法的演进史。     

也论化学元素周期表的形成和发展

In the time order, the author proposes that the discovery and development of the periodic table of chemical elements are divided into four stages:point→1D→2D→3D. This article cites the main historical facts and documents available to unscramble the above four stages, which will facilitate the teaching and scientific research of the periodic table.     

基于科学本质教育的化学教科书设计——以元素周期律的发现和学习为例

理解科学本质是科学教育始终追求的一个重要目标。教科书作为学校教育最主要的教材,应重视以科学史为线索,实现科学本质教育的任务。元素周期律作为化学科学重要的基本理论,它的发现过程充满了科学家的探索和智慧,蕴含着丰富的科学本质教育的素材。化学教科书的设计应充分重视这一素材,从内容和方法两个维度对学生进行科学本质教育。     

现代元素周期律的化学微观视角探析*

由门捷列夫元素周期表到现代元素周期律的发展,将人们的关注点从元素化学性质相似性的宏观考量转移到原子电子组态周期性递变的微观探析上来。对原子核外电子排布“构造原理”的产生、发展及其作用展开讨论,尝试对元素周期律的微观本质进行探析。     

元素周期律的进一步探究

从广义对角相似律、奇偶周期相似律、大周期相似律、元素数目规律、周期表是否存在上限等诸方面对元素周期表和周期律进行深入探究,结果表明元素周期律和周期表在化学发展史上占据着重要的位置,仍是自然科学发展的重要工具。     

迈向元素周期律的第一人:约翰·沃尔夫冈·杜布莱纳

德国化学家约翰·沃尔夫冈·杜布莱纳于1829年提出元素三组律,是探索元素性质与原子量之间关系的第一人,开创了元素周期律研究的先河,同时也在化学的许多其他领域做出了重大贡献。2019年是国际化学元素周期表年,同时也是杜布莱纳逝世170周年,谨以此文纪念这位伟大的学者。     

配位化学的创始与现代化

本文扼要介绍了韦尔纳配位理论的第一篇文章的内容，讨论了配位化学的发展和现代化。配合物稳定性决定于多种作用力与组分间的互补性和拓扑约束性。     

基于数据分析能力培养的元素周期律教学实践研究

从教学现状中发现学生对元素周期律知识的灵活运用能力不够,反思物质结构及元素周期律知识的教学地位及价值,确定以数据分析能力为培养目标进行教学设计以及对该教学设计实践后的效果分析,为促进教师转变观念,培养学生思维发展和提高课堂教学效果提供参考。     

The Nature of Bonding between Argon and Mixed Gold–Silver Trimers

The controversial nature of chemical bonding between noble gases and noble metals is addressed. Experimental evidence of exceptionally strong Au? Ar bonds in Ar complexes of mixed Au? Ag trimers is presented. IR spectra reveal an enormous influence of the attached Ar atoms on vibrational modes, particularly in Au‐rich trimers, where Ar atoms are heavily involved owing to a relativistically enhanced covalency. In Ag‐rich trimers, vibrational transitions of the metal framework predominate, indicating a pure electrostatic character of the Ag? Ar bonds. The experimental findings are analyzed by means of DFT calculations, which show how the relativistic differences between Au and Ag are manifested in stronger Au? Ar binding energies. Because of the ability to vary composition and charge distribution, the trimers serve as ideal model systems to study the chemical nature of the bonding of noble gases to closed‐shell systems containing gold.     

思想和技术融合下铝元素概念的演变

从认识铝的化合物到铝元素预言的产生、金属单质的获取、原子质量的测定,直至同位素的发现,铝元素概念的发展大致可分为萌芽、形成和新的认识3个主要时期.相应的,关于铝元素的认识经历了从假说到客观实在,从定性到定量,从宏观到微观的发展历程.铝元素概念的演变浓缩着人类科学认知的过程,体现了科学思想和科学技术的进步.     

Molecular complexes of organometallic molecules with noble gases: the rotational spectrum of dimethylsilane-argon.

The rotational spectrum of the molecular complex dimethylsilane-argon was investigated by free-jet absorption millimeter-wave and molecular-beam Fourier transform spectroscopy. The absolute energy minimum corresponds to a conformation in which the argon atom lies in the plane of symmetry of dimethylsilane, perpendicular to the C-Si-C plane. The distance of Ar atom is tilted 14 degrees away from the Si atom. The zero-point dissociation energy was estimated from the centrifugal distortion constant D(J) to be 2.2 kJ mol(-1). Small splitting, due to tunneling of the Ar atom and internal rotation of the two methyl groups, was observed, measured, and used to determine the potential energy surface for these motions.     

Mass Spectrometric Observation of Doubly Charged Alkaline‐Earth Argon Ions

Doubly charged diatomic ions MAr²⁺ where M=Mg, Ca, Sr or Ba have been observed by mass spectrometry with an inductively coupled plasma ion source. Abundance ratios are quite high, 0.1 % for MgAr²⁺, 0.4 % for CaAr²⁺, 0.2 % for SrAr²⁺ and 0.1 % for BaAr²⁺ relative to the corresponding doubly charged atomic ions M²⁺. It is assumed that these molecular ions are formed through reactions of the doubly charged metal ions with neutral argon atoms within the ion source. Bond dissociation energies (D₀) were calculated and agree well with previously published values. The abundance ratios MAr⁺/M⁺ and MAr²⁺/M²⁺ generally follow the predicted bond dissociation energies with the exception of MgAr²⁺. Mg²⁺ should form the strongest bond with Ar [D₀ (MgAr²⁺)=124 to 130 kJ mol^?1] but its relative abundance is similar to that of the weakest bound BaAr²⁺ (D₀=34 to 42 kJ mol^?1). The relative abundances of the various MAr²⁺ ions are higher than those expected from an argon plasma at T=6000 K, indicating that collisions during ion extraction reduce the abundance of the MAr²⁺ ions relative to the composition in the source. The corresponding singly charged MAr⁺ ions are also observed but occur at about three orders of magnitude lower intensity than MAr²⁺.     

ChemInform Abstract: Noble Gas Supported B3+ Cluster: Formation of Strong Covalent Noble Gas—Boron Bonds.

B₃Ng₃⁺ (Ng: He—Rn) complexes are characterized by quantum chemical MP2 and CCSD(T) calculations.