Physics Chapter on Radiation and Atoms

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Questions and Answers

What type of radiation is produced when highly accelerated electrons bombard a target?

Beta particle

Alpha particle

X-ray (correct)

Gamma-ray

Which of these is a characteristic of radiation when interacting with matter?

Absorption, which can be a property of both visible light and x-rays (correct)

Refraction, of all types of radiation

Reflection, only of visible light

Scattering, of alpha particles

Which of the following is a property of neutrons?

They have a negative electrical charge.

They bind with electrons via strong force.

They have no electrical charge. (correct)

They are lighter than protons.

What phenomenon describes the dual nature of electromagnetic energy, behaving like both a wave and a particle?

Wave-particle duality Signup and view all the answers

What type of material is typically needed for shielding against the intensity of radiation, particularly X-rays and gamma-rays?

High atomic number material Signup and view all the answers

Which of the following best describes the arrangement of an atom, as proposed by Niels Bohr?

A central positive nucleus with surrounding negative electrons in orbits. Signup and view all the answers

Which type of radiation is characterized by a helium nucleus consisting of 2 protons and 2 neutrons?

Alpha particle Signup and view all the answers

What is the primary difference between isotopes of the same element?

They have a different number of neutrons. Signup and view all the answers

Which of these best describes how alpha particles lose energy?

Through collisions with atomic electrons causing ionizations Signup and view all the answers

What does the atomic number (Z) of an element represent?

The number of protons in the nucleus. Signup and view all the answers

What is the definition of a nuclide?

Another name for an isotope of the element. Signup and view all the answers

Why do alpha particles have a short range in materials?

They lose energy quickly due to their double positive charge and large mass Signup and view all the answers

Which of the following is considered a natural source of radiation?

Cosmic rays Signup and view all the answers

What distinguishes the energy spectrum of beta particles from that of alpha particles?

Beta particles have a continuous energy spectrum, while alpha have a discrete Signup and view all the answers

Which phenomenon is associated with high-speed electrons losing energy through interaction with the nuclear field in dense material?

Bremsstrahlung Signup and view all the answers

In a neutral atom, what is true about the number of electrons and protons?

The number of electrons is equal to the number of protons. Signup and view all the answers

What is the significance of understanding how radiation interacts with cells?

To protect oneself and the patient from biological changes. Signup and view all the answers

How does the ionizing capability of beta particle compare to that of an alpha particle?

Beta particles cause less ionisation per unit length than alpha particles. Signup and view all the answers

What does the symbol 'A' represent within the notation $ , ^A_ZX $ for an element?

Mass number. Signup and view all the answers

Considering their properties, which type of radiation poses a greater external hazard?

Beta particles Signup and view all the answers

Which type of ionizing radiation is more likely to pose an internal hazard than an external hazard?

Alpha particles Signup and view all the answers

Study Notes

Course Information

Course title: Radiation Biology & Safety
Course code: MRD441
University: Universiti Teknologi MARA

Course Objectives

Describe the basic structure of an atom
List the types of radiation
Describe different types of radiation
Differentiate between different types of radiation
Describe the radiation effects on prenatal and postnatal life
Explain the stochastic and deterministic effects of low-level radiation over an extended period of time
Explain radiographic equipment specifications for radiation protection purposes
Explain methods of radiation detection and its measurement

Atomic Structure

Elements arranged according to their atomic weight (Mendeleev, 1870)
Atom contains a central positive nucleus with surrounding orbits containing negatively charged electrons (Bohr, 1913)
Nucleus contains neutrons (neutral) and protons (+)
Electrons (-) are outside the nucleus
The number of electrons equals the number of protons in a neutral atom

Periodic Table

Elements are arranged by atomic number (row) and electron configuration (group)
Includes elements, their symbols, and atomic weights
Categorization of elements includes metals, nonmetals, gases, synthetics, alkali, alkali earths, and more

Types of Radiation

Ionizing radiation
- Charged particle beams (directly ionizing) - alpha particles, beta particles, etc.
- Uncharged particle beams (indirectly ionizing) - neutrons, etc.
- Electromagnetic waves (indirectly ionizing) - X-rays, gamma rays, etc.
Nonionizing radiation
- Electromagnetic waves - ultraviolet rays, infrared rays, visible light, etc.
Radiation usually refers to ionizing radiation

Atomic Structure (Continued)

Atomic number (Z) - number of protons in an atom
Mass number (A) - sum of protons and neutrons in an atom
Isotopes - atoms of the same element with different numbers of neutrons
Nuclides - alternative name for isotopes

History of Radiation

Early radiation workers (e.g., radium miners, luminous dial painters)
Atomic warfare
Power plant accidents (e.g., Chernobyl)

Biological Response to Radiation

X-ray interactions with human tissue cause biological changes
Technologists must understand cellular biology and radiation interactions to protect themselves and patients

Types of Ionizing Radiation (Specific examples)

Alpha particles
- Helium nucleus (2 protons, 2 neutrons)
- Emitted from naturally occurring radioactive nuclides (e.g. Uranium, Thorium)
- Lose energy quickly, short range, significant internal hazard
- Easily stopped by paper or clothing
Beta particles
- High-speed electrons
- Emitted from radioactive nuclides
- Lose energy gradually, intermediate range, external and internal hazard
- Stopped by aluminum
Gamma rays
- Electromagnetic waves/photons
- Emitted by radioactive nuclides
- High energy, long range, significant external hazard
- Stopped by lead
X-rays
- Electromagnetic waves/photons
- Produced when high-speed electrons hit a target
- High energy, long range, significant external hazard
- Stopped by lead

Radiation Interaction with Materials/Body

Light interacts through reflection, transmission, attenuation, and absorption
X-rays interact with matter through scattering, transmission, attenuation, absorption, radiopaque/radiolucent properties
Atoms, molecules, and cells are effected by radiation, potentially causing changes within the structures

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Description

Test your knowledge on various aspects of radiation, including types produced by accelerated electrons and characteristics when interacting with matter. Additionally, explore the properties of neutrons, the atomic structure proposed by Niels Bohr, and the differences between isotopes. This quiz covers essential concepts related to radiation and atomic physics.