Inaugurated by IN-SPACe
ISRO Registered Space Tutor
S7-SA5-0364
What are Diamagnetic Substances (Solid State)?
Grade Level:
Class 12
AI/ML, Physics, Biotechnology, FinTech, EVs, Space Technology, Climate Science, Blockchain, Medicine, Engineering, Law, Economics
Definition
What is it?
Diamagnetic substances are materials that are weakly repelled by an external magnetic field. They do not have permanent magnetic dipoles and get temporarily magnetized in the opposite direction of the applied field.
Simple Example
Quick Example
Imagine you have two magnets. If you bring a small piece of wood near one magnet, nothing much happens. That wood is like a diamagnetic substance – it doesn't get attracted or strongly repelled. It shows a very, very slight push away from the magnet, but it's so weak you can't feel it.
Worked Example
Step-by-Step
Let's understand how diamagnetism works at a basic level.
Step 1: Consider an atom in a diamagnetic substance, like water (H2O).
---Step 2: Each electron orbiting the nucleus creates a tiny magnetic field. Normally, these fields cancel each other out because electrons orbit in pairs with opposite spins.
---Step 3: When an external magnetic field is applied, it slightly changes the motion of these orbiting electrons.
---Step 4: This change in electron motion creates a tiny induced magnetic field within the substance.
---Step 5: This induced magnetic field is always in the opposite direction to the external magnetic field.
---Step 6: Because the induced field opposes the external field, the substance is weakly repelled. This weak repulsion is diamagnetism.
---Answer: Diamagnetic substances are repelled because the external magnetic field induces an opposing magnetic field within them.
Why It Matters
Understanding diamagnetism is key in fields like Medicine for MRI machines, where strong magnetic fields are used to create images of the body. In Engineering, it helps design materials with specific magnetic properties for electronics. It even influences how some levitation technologies might work in the future.
Common Mistakes
MISTAKE: Thinking diamagnetic substances are attracted to magnets. | CORRECTION: Diamagnetic substances are *weakly repelled* by magnetic fields, not attracted.
MISTAKE: Believing diamagnetic substances have unpaired electrons. | CORRECTION: Diamagnetic substances have *all electrons paired*, which causes their individual magnetic moments to cancel out.
MISTAKE: Confusing diamagnetism with paramagnetism or ferromagnetism. | CORRECTION: Diamagnetism is a *very weak repulsion*, while paramagnetism is *weak attraction* and ferromagnetism is *strong attraction* and permanent magnetization.
Practice Questions
Try It Yourself
QUESTION: Which of the following is a diamagnetic substance: Iron, Copper, or Oxygen? | ANSWER: Copper
QUESTION: Why do diamagnetic substances show repulsion in a magnetic field? | ANSWER: Because the external magnetic field induces an opposing magnetic field within the substance.
QUESTION: If a material has all its electron spins paired, what type of magnetic behavior would it most likely exhibit? Explain briefly. | ANSWER: It would most likely exhibit diamagnetic behavior because the paired electrons mean their individual magnetic moments cancel out, leading to no net permanent magnetic moment.
MCQ
Quick Quiz
Which statement best describes a diamagnetic substance?
Strongly attracted to a magnetic field
Weakly repelled by a magnetic field
Strongly repelled by a magnetic field
Unaffected by a magnetic field
The Correct Answer Is:
B
Diamagnetic substances are characterized by being weakly repelled by an external magnetic field. Options A, C, and D describe other types of magnetic behavior or no interaction.
Real World Connection
In the Real World
You might not see diamagnetism directly in daily life, but it's crucial in advanced tech. For example, in MRI scanners (Magnetic Resonance Imaging) used in hospitals in India, the strong magnetic fields interact with the diamagnetic properties of water in our body to create detailed images of organs and tissues, helping doctors diagnose diseases without surgery.
Key Vocabulary
Key Terms
MAGNETIC FIELD: A region around a magnetic material or a moving electric charge within which the force of magnetism acts. | REPULSION: The force that pushes two objects away from each other. | INDUCED: Caused or brought about by something else. | ELECTRON PAIRS: Two electrons occupying the same orbital with opposite spins. | PERMANENT DIPOLE: A constant magnetic moment present even without an external field.
What's Next
What to Learn Next
Now that you understand diamagnetism, next you should explore 'What are Paramagnetic Substances?'. This will help you compare and contrast different magnetic behaviors and understand why some materials are weakly attracted to magnets.
