6.7 The Structure of The Atom

1. 6.7 The Structure of The Atom (p.234-240)

2. Inside the Atom: atom • The _____is the smallest particle of an element that has the same properties of the element. • Atoms do not have a CHARGE. • The atom is composed of many smaller ___________particles. • 3 Main Types of Subatomic Particles: __________and __________, which make up the ________and ___________, which move in specific regions around the nucleus. subatomic protons nucleus electrons neutrons

4. Terminology Atomic Number • ________________:The number of protons in the nucleus of an atom. This identifies an atom as a particular element (the # of protons never changes). • ______________: the ________ mass of the _________ occurring isotopes of an element. • The sum of the number of protons & neutrons in an atom. • Protons and neutrons contribute nearly all the mass of an atom. naturally Atomic Mass average

5. Atomic Mass • Atomic Mass refers to the “weight” of the atom. • It is derived at by adding the number of protons with the number of neutrons. This is a helium atom. Its atomic mass is 4 (protons plus neutrons). What is its atomic number? H

6. Terminology • _______________________: the number of rings around the nucleus that contain the electrons. (Period Number). • _____________: The electrons in the outermost shell (Group Number) • ___________: The outermost shell Orbits / Shells / Energy Levels Valence Electron Valence Shell

7. * *

8. Atomic Mass Unit (AMU) • The unit of measurement for an atom is an AMU. It stands for atomic mass unit. • One AMU is equal to the mass of one proton.

9. Atomic Mass Unit (AMU) • There are 6 X 1023or 600,000,000,000,000,000,000,000 AMU’s in one gram. • Remember that electrons are 2000 times smaller than one AMU.

10. Fill in the diagram on the following page… you MUST know all of these terms…. Valence Shell 2 Key Terms Try to find the following on the image… • Nucleus • Protons • Neutrons • Electrons • Orbits / shells / energy levels • Valence Shell • Valence Electron 1 Lets See What You Know 3 4 Energy Levels Valence Electrons

11. Representing Elements: • The symbols that are used to represent the elements are the same throughout the world – the system is international. • A common notation that scientists use to represent atoms of elements is called the _______________ ____________ ______________, which includes the _______ ___________ and ________ _____________ of an atom of an element. Standard Atomic Notation Atomic Number Atomic Mass

12. ? 3 ? 2 Review…. # of… in an ATOM of Carbon Protons = Neutrons = Electrons = Overall Charge = # of Shells = # of Valence Electrons = ? 1 ? 4 ? 5

13. Representing Atoms: • The Bohr-Rutherford model is a convenient way of representing the atomic structure of an element. • How to draw a Bohr-Rutherford Diagram: PAGE 236

14. Examples – from class note

15. Potassium (K) 2-8-8-1 Sodium (Na) 2-8-1Hydrogen (H) 1 Oxygen (O) 2-6 • Carbon (C) 2-4 Silicon (Si) 2-8-4 Magnesium (Mg) 2-8-2 Aluminum (Al) 2-8-3 • Chlorine (Cl) 2-8-7 Argon (Ar) 2-8-8 Boron (B) 2-3 Calcium (Ca) 2-8-8-2 • Lithium (Li) 2-1 Sulfur (S) 2-8-6 Neon (Ne) 2-8

16. Lewis Dot Diagram • Simply show the number of valence electrons. • No reference to number of shells/orbits/energy levels

17. HW Questions • Pg 240 • Q 1-8