Problem 148 - A Complete Resource Book in Chemistry for JEE Main

Question

Which of the following nuclear reactions will generate an isotope? (a) positron emission (b) \(\alpha\) particle emission (c) \(\beta\) particle emission (d) neutron particle emission

Step-by-Step Solution

Answer

Neutron particle emission generates an isotope.

Step 1: Identifying the Effects of Each Reaction Type

First, let's understand the effects of each nuclear reaction. In positron emission, a proton in the nucleus is converted into a neutron, releasing a positron. In alpha particle emission, the nucleus loses 2 protons and 2 neutrons. In beta particle emission, a neutron is converted into a proton, emitting a beta particle. Finally, neutron particle emission removes a neutron from the nucleus without changing the element.

Step 2: Evaluating Isotope Formation

An isotope is a variant of a particular chemical element which differs in neutron number, while the proton number (atomic number) stays the same. Thus, reactions that result in a change in the number of neutrons and not protons of the same element produce isotopes.

Step 3: Analyzing Each Reaction Type for Isotope Formation

- **Positron Emission:** Changes a proton to a neutron, altering the element. - **Alpha Particle Emission:** Changes both protons and neutrons, altering the element. - **Beta Particle Emission:** Changes a neutron to a proton, altering the element. - **Neutron Particle Emission:** Changes only the number of neutrons.

Step 4: Identifying Isotope-Producing Reaction

The neutron particle emission removes a neutron from the nucleus but keeps the element's atomic number (protons) the same while altering its mass number. As such, it results in a different isotope of the element.

Key Concepts

Isotope Formation

An isotope is a form of a chemical element that retains its proton number but has a different number of neutrons compared to other forms of the same element. This means that even though isotopes have different atomic masses, their atomic numbers remain unchanged. You'll find isotopes labeled with the element name followed by their mass number, like Carbon-12 and Carbon-13.
To better understand isotopes, remember these core points:

• The atomic number tells us the number of protons in an atom, which defines the element.
• Neutrons, however, affect the mass of the atom and can vary without changing the element itself.
• Producing isotopes involves nuclear reactions where only the number of neutrons is altered while keeping the atomic number the same.

Such changes usually occur during specific nuclear reactions, and are essential in fields like nuclear chemistry and medicine, where isotopes are used for tracing and diagnostic purposes.

Neutron Particle Emission

Neutron particle emission is a process where a neutron is expelled from the nucleus without changing the atomic number of the atom. This reaction is a key player in creating isotopes, given that it solely modifies neutron count, leading to a different mass number while keeping the element type intact.
Key takeaways include:

• Neutron particle emission does not alter the element because it doesn't affect the atomic number.
• This emission helps in forming isotopes by changing only the mass number.
• It provides valuable insights into the structure and stability of nucleons within the nucleus.

Understanding neutron particle emission allows scientists to manipulate isotopes, aiding in advancements in materials science and energy applications.

Nuclear Chemistry

Nuclear chemistry focuses on the reactions and processes that occur within the nucleus of an atom. These reactions often involve changes to the nucleus, leading to the formation of new elements or isotopes, and are distinct from chemical reactions where electrons are rearranged.
Important aspects to cover include:

• It studies radioactive decay, a process where unstable nuclei lose energy by emitting radiation.
• Nuclear reactions can change one element into another, a process not possible with conventional chemical reactions.
• Applications of nuclear chemistry are widespread, from medical imaging and cancer treatment to power generation and archaeological dating.

By understanding nuclear chemistry, we can harness these powerful reactions for various scientific and practical gains, particularly through isotope manipulation in medicine and industry.