mass number

简明释义

质量数

英英释义

例句

1.The mass number 质量数 of an atom is the total number of protons and neutrons in its nucleus.

一个原子的质量数 质量数是其原子核中质子和中子的总数。

2.When studying isotopes, the mass number 质量数 helps distinguish between different forms of the same element.

在研究同位素时，质量数 质量数有助于区分同一元素的不同形式。

3.Carbon-12 has a mass number 质量数 of 12, which means it has 6 protons and 6 neutrons.

碳-12的质量数 质量数为12，这意味着它有6个质子和6个中子。

4.Uranium-238 has a mass number 质量数 of 238, indicating it has 146 neutrons.

铀-238的质量数 质量数为238，表明它有146个中子。

5.To find the mass number 质量数, simply add the number of protons to the number of neutrons.

要找到质量数 质量数，只需将质子的数量与中子的数量相加。

作文

Understanding the concept of mass number is crucial for anyone studying chemistry or physics. The mass number, defined as the total number of protons and neutrons in an atomic nucleus, plays a significant role in determining the properties of an element. In simpler terms, it helps us understand how heavy an atom is and its stability. For example, consider carbon, which has an atomic number of 6. This means it has six protons in its nucleus. The most common isotope of carbon, carbon-12, has six neutrons, giving it a mass number of 12. This information is essential not only for scientific calculations but also for practical applications such as radiocarbon dating, where the mass number helps determine the age of ancient organic materials.The mass number is often confused with atomic mass, but they are not the same. Atomic mass is the weighted average of all isotopes of an element, while the mass number refers specifically to the count of nucleons in a particular isotope. This distinction is important when discussing isotopes, which are variants of elements that have the same number of protons but different numbers of neutrons. For instance, hydrogen has three isotopes: protium (with a mass number of 1), deuterium (with a mass number of 2), and tritium (with a mass number of 3). Each of these isotopes behaves differently in chemical reactions due to their varying mass numbers.Furthermore, understanding the mass number is essential in nuclear chemistry and physics. The stability of an atomic nucleus is influenced by the ratio of protons to neutrons. If the mass number is too high or too low compared to the number of protons, the nucleus may become unstable and undergo radioactive decay. This process is critical in various applications, including nuclear power generation and medical treatments using radioactive isotopes. For example, iodine-131, which has a mass number of 131, is used in medicine for treating thyroid conditions. Its mass number indicates its composition and helps medical professionals understand its behavior in the human body.In summary, the mass number is a fundamental concept in understanding the structure and behavior of atoms. It provides vital information about the composition of an atom’s nucleus and influences its chemical and physical properties. Whether you are studying the periodic table, exploring the nature of isotopes, or delving into nuclear reactions, mastering the concept of mass number will enhance your comprehension of the scientific world. By appreciating the significance of the mass number, students and enthusiasts can develop a deeper understanding of the elements that make up our universe and the intricate processes that govern their interactions.

理解质量数的概念对于任何学习化学或物理的人来说都是至关重要的。质量数被定义为原子核中质子和中子的总数，它在决定元素的性质方面发挥着重要作用。简单来说，它帮助我们理解一个原子的重量及其稳定性。例如，考虑碳，它的原子序数为6。这意味着它的核中有六个质子。最常见的碳同位素，碳-12，具有六个中子，因此其质量数为12。这些信息对于科学计算以及实际应用（如放射性碳测年）至关重要，其中质量数有助于确定古代有机材料的年龄。质量数常常与原子质量混淆，但它们并不相同。原子质量是元素所有同位素的加权平均值，而质量数特指某一特定同位素中核子（质子和中子）的数量。这一区别在讨论同位素时非常重要，同位素是质子数相同但中子数不同的元素变体。例如，氢有三种同位素：氕（质量数为1）、氘（质量数为2）和氚（质量数为3）。由于它们的质量数不同，这些同位素在化学反应中的行为也不同。此外，理解质量数在核化学和物理学中至关重要。原子核的稳定性受质子与中子比例的影响。如果质量数相对于质子数过高或过低，核可能变得不稳定并发生放射性衰变。这个过程在各种应用中至关重要，包括核能发电和使用放射性同位素的医疗治疗。例如，碘-131，其质量数为131，用于治疗甲状腺疾病。它的质量数指示其组成，并帮助医疗专业人员理解其在人体内的行为。总之，质量数是理解原子结构和行为的基本概念。它提供关于原子核组成的重要信息，并影响其化学和物理性质。无论您是在学习周期表、探索同位素的性质，还是深入研究核反应，掌握质量数的概念将增强您对科学世界的理解。通过欣赏质量数的重要性，学生和爱好者可以更深入地理解构成我们宇宙的元素及其相互作用的复杂过程。