PPT-4.2 – NOTES The Mass of the Atom

III How atoms differ A Atomic Number Equal to the number of protons never changes equals the number of electrons if AND ONLY IF the atom is neutral Moseley discovered each atom has a unique number of protons in the nucleus. A Look Into the Ultimate. ESSENTIAL QUESTIONS:. Why was an image of individual atoms considered such an important breakthrough?. How scientists discovered the component particles within atoms?. How can we possibly know anything about atomic structures?. Atoms and Molecules and Ions, Oh My!. The Atom – Structure and Theory. Early History. The Greeks tried to explain chemical changes such as:. Dying cloth and skins. Writing with charcoal. Finding medicines in plants. Atomos: Not to Be Cut. The History of . the Atom and the Atomic . Theory. Atomic Models. This model of the atom may look familiar to you. This is . the Bohr model. . In this model, the nucleus is orbited by electrons, which are in different energy levels. . Unit 11. The Atomic Nucleus. Identification of Three Subatomic Particles (3.5). Arrangement of Subatomic Particles (3.5). Definitions of atomic number, mass number, isotope (3.5). Three Basic Subatomic Particles . Most matter is a molecular mixture of these 118 different elements. . Mostly THESE 12 elements.. Most matter is a molecular mixture of these 118 different elements. . Mostly THESE 12 elements.. They are the letters of the MATTER alphabet.. Today you need your notebook and Laptop. Open the PowerPoint on the weebly. . In your notebook answer the following questions: . What two particles does the nucleus contain?. Which subatomic particle has the smallest mass?. DO NOW:. 1. 2. 3. 4. The Greek Concept of . Atomos. : . The . Indivisible Atom. . Around 440 BC, Leucippus originated the atom concept.. His pupil, Democritus (c460-371 BC) extended it . There are five major points to their atomic idea.. Atoms are the fundamental blocks of matter…. Chapter Big Idea. Section 1: Early Ideas About Matter. What are the similarities and differences of the atomic models of Democritus, Aristotle, and Dalton?. Atomic Theory Origin The earliest recorded idea about the existence of atoms comes from a Greek philosopher named Democritus @ 400 BC He theorized that if you were to cut an object in half, then cut it in half again and again over and over… The Atom Chapter 11 Section 2 What is an atom made of? Inside the Nucleus Atomic Mass Unit – unit of mass that describes the mass of an atom or molecule. Protons = POSITIVE charge (1 proton = 1amu.) Bell Work. Talk to people around you and write down anything you know about atom. Do not be shy about any idea!. Draw . an atom how you imagine it . (. 1 min. .). Do atoms have mass?. We often say “something has charge”. What does it mean to have charge?. Learn how the efficiency of a chemical reaction can be measured in terms of percentage yield.. Success criteria. I can plan and complete an experiment . I can calculate the percentage yield . Preparation of zinc sulphate. Our view of the atom has changed over time. 2. Aristotle . (460 B.C. – 370 B.C.). emphasized that nature consisted of four elements: air, earth, fire, and water. did not believe in discontinuous or separate atoms, but felt that matter was continuous. Rutherford proposed that most of the mass of the atom was concentrated. . at the atom’s center. . Rutherford’s Model of the Atom. Rutherford’s experiment suggested that an atom’s positive charge is concentrated in the center of the atom .