Laws of Conservation of Mass and Ion Formation

This page delves deeper into atomic structure and chemical reactions, focusing on the conservation of mass and the formation of ions. It explains how the mass number of an atom is calculated and introduces the concept of ions, which are atoms or groups of atoms with an electric charge.

Definition: The mass number of an atom is the sum of its protons and neutrons.

Vocabulary: An ion is an atom or group of atoms that has gained or lost electrons, resulting in a positive or negative charge.

The page describes how elements can gain or lose electrons during chemical reactions, leading to the formation of positive or negative ions. It also outlines the general behavior of metals and non-metals in these processes.

Example: Metals tend to lose electrons, forming positive ions, while non-metals gain electrons to form negative ions.

Historical contributions to atomic theory are mentioned, including J.J. Thomson's discovery of electrons and Rutherford's gold foil experiment, which led to the nuclear model of the atom.

Highlight: Rutherford's experiment showed that most of an atom's mass is concentrated in a small, positively charged nucleus.

The concept of isotopes is introduced, explaining that these are atoms of the same element with different numbers of neutrons.

Definition: Isotopes are atoms with the same number of protons but different numbers of neutrons in their nuclei.

This page provides a comprehensive overview of atomic structure, ion formation, and the historical experiments that shaped our understanding of the atom, reinforcing the atomic structure and isotopes study guide with practical examples and key discoveries in the field.