Difference Between Stable Isotopes and Radioisotopes

关键区别 - 稳定的同位素与放射性同位素

同位素是不同形式的相同化学元件的不同形式atomic masses. This means isotopes of a certain chemical element have the sameatomic numberbut different atomic masses. This is because these isotopes have different numbers ofneutronsin their atomic nuclei. Some isotopes are stable whereas some are unstable. Stable isotopes are naturally occurring forms of chemical elements. These stable isotopes can occur naturally in atomic form or in combination with other atoms. Unstable isotopes undergo radioactive decay until they get a stable state. These isotopes are known as radioisotopes. The key difference between stable isotopes and radioisotopes is thatstable isotopes do not undergo radioactive decay whereas radioisotopes undergo radioactive decay.

内容

1.Overview and Key Difference
2.什么是稳定同位素
3.What are Radioisotopes
4.并排比较 - 稳定的同位素与放射性同位素的表格形式
5.概括

什么是稳定同位素?

稳定的同位素是具有稳定核的同一化学元件的不同形式。这些原子具有相同的原子数（数量protonsin the atomic nuclei) because they belong to the same chemical element, but the atomic masses are different from each other because they have different numbers of neutrons in the atomic nuclei.

Stable isotopes are non-radioactive due to the stability of the atomic nuclei. Therefore, these atoms do not emit radiation. A particular chemical element can have more than one stable isotope. But in some chemical elements, all the isotopes are unstable; hence, they are radioactive.

The stability of atomic nuclei depends on two basic factors:

1. Ratio between protons and neutrons
2. Sum of protons and neutrons

“Magic numbers” is a chemical concept that is used to determine the stability of a certain atomic nucleus. It gives the number of electrons present in stable isotopes. The magic number can be either the number of protons or even the number of neutrons present in the nucleus.

魔术数：2、8、20、28、50、82和126

If the atomic number of an isotope is equal to one of above numbers, then it is a stable isotope. In addition, if an isotope has 114 protons, it is a stable isotope. Moreover, if there are 126 or 184 neutrons present, they are also stable isotopes. In addition, if the ratios between protons and neutrons in an atom are even numbers, then these isotopes are most probably stable isotopes.

What are Radioisotopes?

放射性同位素是经历放射性衰减的化学元素的不稳定同位素。这些同位素会经历放射性衰减，因为它们具有不稳定的原子核。大多数化学元素具有一个或多个放射性同位素，而某些化学元素仅具有放射性同位素（例如：Uranium).

Radioactive isotopes are unstable due to several reasons:

1. 与质子的数量相比，原子核中有大量中子的存在

• 在这些放射性同位素中，中子在放射性衰减期间转化为质子和电子。

2. Presence of a high number of protons in the atomic nucleus

• In these radioisotopes, protons are converted into neutrons and positrons.

3. 存在大量质子和电子

• These radioisotopes undergoα衰变其中两个质子和两个中子被排放为α颗粒

What is the Difference Between Stable Isotopes and Radioisotopes?

Stable Isotopes vs Radioisotopes
稳定的同位素是具有稳定核的同一化学元件的不同形式。	放射性同位素是经历放射性衰减的化学元素的不稳定同位素。
Stability
Stable isotopes are very stable and do not undergo radioactive decay.	Radioisotopes are very unstable and undergo radioactive decay to obtain a stable state.
Protons
114个质子的存在使同位素成为稳定的同位素。	Presence of a high number of protons makes an isotope a radioisotope.
中子
存在126或184个中子使同位素成为稳定的同位素。	neutr的数量ons in the atomic radius is higher than the number of protons.

摘要 - 稳定的同位素与放射性同位素

同位素是具有相同原子数但原子质不同的相同化学元件的原子。有些同位素是稳定的，而另一些则不稳定。稳定的同位素是这些化学元件的天然形式。不稳定的同位素也称为放射性同位素，因为这些同位素会经历放射性衰减以获得稳定的状态。稳定的同位素和放射性同位素之间的关键区别是基于它们经历放射性衰减的能力。

Reference:

1. “Stable isotope ratio.” Wikipedia, Wikimedia Foundation, 27 Feb. 2018,Available here.
2.“什么是放射性同位素？”Foro核，Available here.
3. Britannica，百科全书的编辑。“魔术数。”2017年7月12日Available here.

Image Courtesy:

1. “Periodic Table by Number of Stable Isotopes” By Nergaal at English Wikipedia(CC BY-SA 3.0)viaCommons Wikimedia
2. “Table isotopes en” By Table_isotopes.svg: Napy1kenobiderivative work: Sjlegg (talk) – Table_isotopes.svg(CC BY-SA 3.0)通过Commons Wikimedia