Physics and Chemistry 3C1 by

THE ATOM

markelbravo1 — 2024-10-04 07:47:36 UTC

Protons: Positively charged particles found in the nucleus (the center) of the atom.
Neutrons: Neutral particles (no charge) also located in the nucleus.
Electrons: Negatively charged particles that orbit the nucleus in various energy levels or shells.

markelbravo1 — 2024-11-22 07:37:29 UTC

Dmitri Mendeleev was a Russian chemist and inventor best known for creating the periodic table of elements. He organized the elements based on their atomic weights and properties, leaving gaps for elements that had not yet been discovered but predicting their characteristics accurately. His work laid the foundation for modern chemistry.

ATOMIC MODEL

markelbravo1 — 2024-11-22 07:37:38 UTC

MOSELEY

markelbravo1 — 2024-11-22 07:41:11 UTC

Henry Moseley (1887–1915) was an English physicist who discovered that an element’s atomic number (number of protons) determines its identity, not its atomic mass. Using X-ray spectroscopy, he formulated Moseley's Law, linking X-ray frequencies to atomic numbers. This clarified the periodic table's structure, predicted missing elements, and modernized atomic theory. He tragically died young in World War I, but his work remains fundamental to science.

ORIGINAL PERIODIC TABLE

markelbravo1 — 2024-11-22 07:43:52 UTC

Knowing the beginning of the periodic table

markelbravo1 — 2024-11-22 07:46:38 UTC

The periodic table began with early attempts to classify elements, like Döbereiner's triads and Newlands' Law of Octaves. In 1869, Mendeleev organized elements by increasing atomic weight and similar properties, leaving gaps for undiscovered elements. In 1913, Moseley improved it by arranging elements by atomic number, creating the modern periodic table.

Video

markelbravo1 — 2024-11-22 07:47:55 UTC