Module 2: History, Terminology, Characteristics & Radiation Safety Worksheet

What term refers to the historical era before Wilhelm Conrad Roentgen's discovery when scientists experimented with electricity in evacuated glass tubes?

The Pre-Roentgen Age

On what exact date did Wilhelm Conrad Roentgen discover X-rays while experimenting with a Crookes tube in his lab?

November 8, 1895

Which chemical compound coated the fluorescent screen that glowed during Roentgen's original Crookes tube experiments?

Barium platinocyanide

Who was the subject of the famous radiograph produced on December 22, 1895, showing bones and rings?

Anna Bertha Roentgen

Which assistant to Thomas Edison suffered severe radiation injuries and died in 1904, marking one of the earliest recognized occupational radiation deaths?

Clarence Dally

What is the approximate wavelength of an X-ray photon?

1 Angstrom (1 x 10^-10 meters)

William Crookes

Pioneer who developed the Crookes tube used in cathode-ray experiments.

Clarence Dally

Edison's assistant whose fatal injuries led Edison to abandon X-ray research

ALARA

Principle stating radiation exposure should be kept “As Low As Reasonably Achievable”

Radiologist

Physician who applies radiation (sound, radio frequencies) in diagnosis and treatment

Radiograph

Photographic record produced by X-rays passing through an object onto a receptor

Inside a Crookes tube, positive ions strike the negatively charged __________________, releasing free electrons

Cathode

When cathode rays strike objects like a Maltese cross inside a vacuum tube, they cast a shadow, proving that cathode rays travel in ______________________ lines.

Straight

The three cardinal rules of radiation protection under ALARA are __________________, __________________, and __________________.

Time, Distance, Shielding

In 1901, Wilhelm Conrad Roentgen was awarded the very first Nobel Prize in __________________ for his discovery.

Physics

The electromagnetic property showing that wavelength and frequency are ______________________ proportional means that as wavelength decreases, frequency increases.

Inversely

Describe two common practices of early X-ray operators in 1895–1896 that led to severe biological damage, and identify two biological effects caused by unshielded exposure.

Early Practices: Early operators placed hands directly in the primary X-ray beam, utilized extremely long exposure times, repeatedly demonstrated exposures publicly, and operated without lead shielding.

Biological Effects: Unrestricted exposure caused erythema (skin redness), severe radiation burns, hair loss (alopecia), skin cancer, and fatal illness

Explain the difference between a Radiologist and a Radiographer (Radiologic Technologist) in terms of medical roles and responsibilities

Radiologist: A specialized physician who interprets medical images and applies radiation/magnetic fields to diagnose and treat patient disease.

Radiographer (Radiologic Technologist): A skilled professional qualified by education to perform imaging procedures and provide patient care under a physician's direction.

State the constant speed (velocity) at which X-rays travel in a vacuum, and explain how an X-ray photon's energy relates to its frequency.

Velocity: X-rays travel at the speed of light: 186,000 miles/sec (3 x 10^8 m/s or 3 x 10^10 cm/s) in a vacuum.

Energy & Frequency: Photon energy is directly proportional to frequency. Higher frequency photons carry higher energy levels and shorter wavelengths