Radioactivity and Nuclear Physics: Exploring Atomic Nuclei
X-rays pass through solid materials, can ionize the air, do not refract in glass, and are not deflected by magnetic fields. They are high-frequency electromagnetic waves emitted by energizing the innermost orbital electrons of atoms.
French physicist Henri Becquerel tried to determine whether some elements spontaneously emitted X-rays.
He found that most elements had no effect, except uranium, which produced rays. It was soon discovered that similar rays were emitted by other elements, such as thorium,
Read MoreUnderstanding Light Behavior: Optics Principles
Optics
The branch of physics that studies the behavior of light, its characteristics, and manifestations. It examines how light interacts with matter.
Ray Optics
In physics, geometrical optics uses Snell’s phenomenological laws of reflection and refraction. Geometrical optics employs the concept of a light beam.
Physical Optics
The branch of optics that treats light as a wave and explains phenomena not explained by considering light as a ray.
Theories About the Nature of Light
Light has a complex nature:
Read MoreElectromagnetism Fundamentals: Charges, Fields, and Circuits
Coulomb’s Law
The magnitude of each electrical force between two stationary point charges is directly proportional to the product of the magnitudes of both charges and inversely proportional to the square of the distance between them.
Coulomb’s law is valid only in stationary conditions, i.e., when there is no charge movement or when the movement occurs at low speeds and in uniform rectilinear trajectories. This is why it is called electrostatic force.
In mathematical terms, the magnitude 
force that
Human Eye Anatomy, Myopia, and Hyperopia: Vision Explained
Eye Anatomy
The human eye, the organ of vision, is an optical system producing images on the retina. This inner eye surface, light-sensitive and roughly spherical (about 25 mm in diameter), displays real, inverted images. Key parts include:
- Sclera: The external, white, opaque, and resistant membrane. In front, it becomes the transparent cornea.
- Cornea: The transparent front part of the eye, allowing light entry.
- Choroid: A membrane lining the eye’s interior (except the cornea), absorbing light.
- Aqueous
Atomic Structure and Wave Phenomena
Item 8: Atomic Structure
Dalton’s Atomic Theory
- Matter consists of individual atoms.
- Atoms are unchanged in chemical reactions.
- Atoms of the same element are identical.
- Atoms of different elements have different masses and chemical properties.
- Chemical compounds are formed by combining two or more atoms of different elements.
- When two or more atoms of different elements combine to form the same compound, they do so in simple whole-number ratios.
- In chemical reactions, atoms are not created nor destroyed,
Evolution of Astronomical Models and Gravity Concepts
Ptolemy’s Geocentric Models
Alexandra Ptolemy (86-165) established a geometric model where the Earth is fixed, and planets revolve around it. The Sun and Moon orbit Earth in circular paths, while other planets follow complex orbits. Planets move in small circles (epicycles) whose centers trace larger circles around Earth. A field of stars also revolves around Earth.
Heliocentric Models
Aristarchus’ Model
Aristarchus of Samos (310-230 BC) proposed a heliocentric model with the Sun at the center, and
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