actinoid contraction

简明释义

锕系元素收缩

英英释义

例句

1.Chemists often discuss actinoid contraction when explaining the similarities between uranium and thorium.

化学家在解释铀和钍之间的相似性时，常常讨论锕系收缩。

2.Understanding actinoid contraction helps predict the chemical behavior of heavy elements.

理解锕系收缩有助于预测重元素的化学行为。

3.The phenomenon of actinoid contraction is crucial for understanding the properties of actinides.

理解锕系收缩现象对于理解锕系元素的性质至关重要。

4.The actinoid contraction affects the ionic radii of the elements in the actinide series.

锕系收缩影响了锕系元素的离子半径。

5.Students learn about actinoid contraction in advanced inorganic chemistry courses.

学生们在高级无机化学课程中学习锕系收缩。

作文

The periodic table of elements is a fascinating representation of the building blocks of matter. Among the various groups of elements, the actinides and lanthanides are particularly intriguing due to their unique properties and behavior. One of the key concepts that help explain the characteristics of these elements is actinoid contraction. This phenomenon refers to the gradual decrease in the size of the atoms of the actinide series as we move from thorium (Th) to lawrencium (Lr). This contraction is largely attributed to the increasing nuclear charge that is not fully offset by the additional electron shielding provided by the f-orbitals. As a result, the effective nuclear charge felt by the outer electrons increases, leading to a stronger attraction between the nucleus and the electrons, which in turn causes the atomic radius to decrease.Understanding actinoid contraction is essential for grasping the trends in chemical reactivity and physical properties of the actinide elements. For instance, as the atomic size decreases, the ionization energies tend to increase, making it more difficult to remove an electron from the outer shell. This can significantly influence the chemical behavior of these elements, particularly in the formation of compounds. The actinides are known for their complex chemistry, often exhibiting multiple oxidation states and forming a variety of compounds with different ligands.Moreover, actinoid contraction plays a crucial role in the comparison of actinides with the lanthanides. While both series exhibit similar trends in contraction, the actinides tend to show a more pronounced effect due to the presence of 5f electrons, which are less effective at shielding than the 4f electrons in the lanthanides. This results in a greater decrease in atomic size across the actinide series compared to the lanthanide series, leading to distinct differences in their chemical and physical properties.The implications of actinoid contraction extend beyond just atomic size; they impact the entire field of nuclear chemistry and materials science. For example, the understanding of this contraction is vital in the development of nuclear fuels and the handling of radioactive waste. The behavior of actinides in solution, their solubility, and their interactions with other elements are all influenced by the principles underlying this contraction. Thus, researchers and chemists must take actinoid contraction into account when designing experiments or applications involving these elements.In conclusion, the concept of actinoid contraction provides valuable insights into the nature of actinide elements and their behavior. By recognizing how atomic size changes across the series and how this affects chemical properties, scientists can better predict and manipulate the reactions and compounds formed by these fascinating elements. The study of actinoid contraction not only enhances our understanding of the periodic table but also opens up new avenues for research and technological advancements in fields such as nuclear energy and advanced materials.

元素周期表是物质基本构件的迷人表现。在各种元素组中，锕系和镧系元素由于其独特的性质和行为而特别引人注目。帮助解释这些元素特征的一个关键概念是锕系收缩。这一现象指的是在锕系系列中，从钍（Th）到劳伦斯（Lr）时，原子大小逐渐减小。这种收缩主要归因于核电荷的增加，而额外电子屏蔽的效果又未能完全抵消。结果，外层电子感受到的有效核电荷增加，导致原子核与电子之间的吸引力增强，从而使原子半径减小。理解锕系收缩对于掌握锕系元素的化学反应性和物理性质的趋势至关重要。例如，随着原子大小的减小，电离能往往增加，使得从外壳中移除电子变得更加困难。这可以显著影响这些元素的化学行为，特别是在化合物的形成方面。锕系元素以其复杂的化学性质而闻名，通常表现出多种氧化态，并与不同配体形成多种化合物。此外，锕系收缩在锕系元素与镧系元素的比较中也起着关键作用。虽然这两个系列都表现出类似的收缩趋势，但由于5f电子的存在，锕系元素的收缩效应往往更为明显，这些电子的屏蔽效果不如镧系元素中的4f电子有效。这导致锕系系列的原子尺寸相较于镧系系列的减小幅度更大，从而导致它们的化学和物理性质存在明显差异。锕系收缩的影响不仅限于原子大小，它们影响整个核化学和材料科学领域。例如，理解这一收缩对于核燃料的开发和放射性废物的处理至关重要。锕系元素在溶液中的行为、其溶解度以及与其他元素的相互作用都受到这一收缩原理的影响。因此，研究人员和化学家在设计涉及这些元素的实验或应用时，必须考虑锕系收缩。总之，锕系收缩的概念为我们提供了对锕系元素及其行为的宝贵见解。通过认识到原子大小如何在系列中变化以及这如何影响化学性质，科学家可以更好地预测和操控这些迷人元素所形成的反应和化合物。对锕系收缩的研究不仅增强了我们对元素周期表的理解，也为核能和先进材料等领域的新研究和技术进步开辟了新途径。