Question

Cathode rays (a) may be positively or negatively charged (b) are a form of electromagnetic radiation similar to visible light (c) have properties identical to \(\beta\) particles (d) have masses that depend on the cathode that emits them

Short answer

The correct answer is (c) have properties identical to \(\beta\) particles

Step-by-step solution

Understand the nature of Cathode Rays

Cathode rays are streams of electrons that are emitted by the cathode in a high-vacuum tube. They are negatively charged particles.

Compare the Properties

Compare the given options with the actual properties of cathode rays. (a) Cathode rays are not positively charged, they are negatively charged. So, this option is incorrect. (b) Cathode rays are not a form of electromagnetic radiation, unlike visible light which is a form of electromagnetic radiation. So, option (b) is also incorrect. (c) \(\beta\) particles are also streams of high-speed electrons emitted during radioactive decay. So, Cathode rays and \(\beta\) particles have identical properties. Hence, option (c) is correct. (d) Cathode rays do not depend on the type of the cathode material. Therefore, option (d) is also incorrect.

Choose Correct Option

Based on the comparison of properties of cathode rays, the correct answer is (c) have properties identical to \(\beta\) particles

Key concepts

Beta Particles

Beta particles are a type of radiation found in radioactive decay processes. They are essentially high-speed electrons or positrons that emerge when a nucleus undergoes transformation. In particular, when a neutron in a radioactive nucleus transforms into a proton, an electron, which we call a beta particle, is emitted. This process is called beta decay.
Compared to other types of radiation, beta particles have a mid-level ability to penetrate materials. They can pass through paper or skin, but are usually stopped by a few millimeters of metal or a thick layer of plastic. Understanding how beta particles penetrate materials is crucial for both their practical use in medicine and industry, and for ensuring safety measures in nuclear environments.
- **Speed and Energy:** Beta particles move at very high speeds, sometimes approaching the speed of light, and they possess significant energy. - **Charge:** Because they are electrons (or positrons in the case of positive beta particles), beta particles have a charge, which allows them to be deflected by magnetic or electric fields.
In nuclear science, the study of beta particles helps us understand the stability of atomic nuclei and the processes that lead to the transformation of one element into another.

Electrons

Electrons are one of the fundamental particles in nature and are essential for the structure and function of all matter. They are tiny, negatively charged particles found in atoms that orbit the positively charged nucleus.
Electrons are responsible for creating bonds between atoms, forming molecules, which in turn make up the substances in the world around us. Their movement and arrangement determine a material's electrical conductivity, magnetism, and chemical reactivity.

• **Basic Properties:** Electrons have negligible mass compared to protons and neutrons, but their presence defines an atom's overall charge.
• **Role in Cathode Rays:** In the context of cathode rays, electrons are liberated from atoms and accelerated through a vacuum, hitting a fluorescent screen and producing visible light. This principle was crucial in the development of early television and computer monitors.
• **Interaction with Fields:** Electrons can easily be influenced by magnetic and electric fields due to their charge. This property is used in many devices, including the Electron Microscope, which allows us to see at a considerably smaller scale than light microscopes.

Understanding electrons helps us unlock many phenomena in physics and chemistry, guiding advancements in technology and materials science.

Radioactive Decay

Radioactive decay is a natural process by which unstable atomic nuclei lose energy by emitting radiation. It is one of the fundamental ways by which elements change into different isotopes or even different elements altogether.
Radioactive decay occurs spontaneously and involves three primary types of radiation: alpha particles, beta particles, and gamma rays. The focus here is on beta decay, where a beta particle (electron or positron) is emitted.

• **Types of Radioactive Decay:** - **Alpha Decay:** The nucleus emits an alpha particle (two protons and two neutrons). - **Beta Decay:** A neutron in the nucleus turns into a proton and emits a beta particle (electron) and an antineutrino. - **Gamma Decay:** The release of excess energy from the nucleus, often accompanying other decay processes as a photon or gamma ray.
• **Role in Nature:** This decay process is essential in understanding the age of rocks and fossils through radioactive dating techniques such as Carbon-14 dating. It's also significant in nuclear power and medicine, where radioactive isotopes are used for diagnosis and treatment.
• **Safety and Applications:** Handling radioactive materials requires safety protocols to prevent exposure, and understanding it allows us to harness radioactivity in a controlled manner for beneficial uses.

The study of radioactive decay not only reveals insights into the intricacies of atomic interactions but also provides practical applications that touch many aspects of our modern life.