Atomic Structure - ICSE Class 8 Chemistry Chapter 4 скачать в хорошем качестве

Atomic Structure - ICSE Class 8 Chemistry Chapter 4

Everything around us is made of tiny particles called atoms, a word that originally meant something that cannot be divided. While early scientists like John Dalton believed atoms were indestructible and indivisible, we now know they are made of even smaller parts called subatomic particles. These include positively charged protons, negatively charged electrons, and neutrons, which have no charge at all. Famous scientists like J.J. Thomson, Ernest Rutherford, and James Chadwick discovered these parts through various experiments, showing that an atom can be broken down into these fundamental units. In the center of every atom is a tiny, dense core called the nucleus, which holds the protons and neutrons. The electrons are much smaller and revolve around this nucleus in fixed paths known as orbits or shells. We identify different elements using the atomic number, which is the number of protons in an atom, and the mass number, which is the total number of protons and neutrons combined. In a normal state, an atom is electrically neutral because it has the same number of positive protons and negative electrons. Atoms always try to become stable, which usually means having a full outer shell of electrons like the noble gases. The number of electrons an atom needs to lose, gain, or share to reach this stable state is called its valency. For instance, metals tend to give away electrons to become positive ions, while non-metals usually take in electrons to become negative ions. By sharing or transferring these electrons, atoms join together to form compounds, which is how everything from water to salt is created. #dohrao #dohraoicseclassh8 #icseclass8 #icse #icseclass8chemistry #dohraoicseclass8chemistry #chemistry