chapter 2 - C h a p t e r 2 / Atomic Structure and...

Info iconThis preview shows pages 1–7. Sign up to view the full content.

View Full Document Right Arrow Icon
C h a p t e r 2 / Atomic Structure and Interatomic Bonding C h a p t e r 2 Atomic Structure and Interatomic Bonding Why Study Atomic Structure and Interatomic Bonding? important properties of materials depend on atomic arrangements This chapter, considers several fundamental and important concepts , atomic structure , electron configurations in atoms and the periodic table , and the various types of primary and secondary interatomic bonds that hold together the atoms comprising a solid. 2.1 Introduction
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
C h a p t e r 2 / Atomic Structure and Interatomic Bonding T his micrograph, which represents the surface of a gold specimen , was taken with a sophisticated atomic force microscope (AFM) . Individual atoms for this (111) crystallographic surface plane are resolved. Also note the dimensional scale (in the nanometer range ) below the micrograph.
Background image of page 2
C h a p t e r 2 / Atomic Structure and Interatomic Bonding 2.2 Fundamental Concepts atom nucleus electrons protons neutrons Electrically charged 1.60 × 10 -19 C 1.67 × 10 -27 kg 9.11 × 10 -31 kg the number of protons characterize Each chemical element the atomic number ( Z ): For a chemical element, the number of protons within the atomic nucleus. = the number of electrons (for an electrically neutral or complete atom) 质质 质质 质质质质 质质质
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
C h a p t e r 2 / Atomic Structure and Interatomic Bonding The atomic number ranges in integral units from 1 for hydrogen to 92 for uranium, Isotopes : Atoms of the same element that have different atomic masses. the number of neutrons ( N ) may be variable. The atomic mass ( A ) of a specific atom may be expressed as the sum of the masses of protons and neutrons within the nucleus. The atomic weight ( A ) The weighted average of the atomic masses of an atom’s naturally occurring isotopes. The atomic mass unit (amu): A measure of atomic mass; one twelfth of the mass of an atom of C 12 , carbon 12 (12C) ( A 12.00000). A 2245 Z + N 质质质 质质质 质质质质质
Background image of page 4
C h a p t e r 2 / Atomic Structure and Interatomic Bonding Mole: The quantity of a substance corresponding to 6.023 × 10 23 atoms or molecules. 1 amu/atom (or molecule) =1 g/mol 2.3 Electrons in Atoms Atomic Models Quantum mechanics. A branch of physics that deals with atomic and subatomic systems; it allows only discrete values of energy that are separated from one another. By contrast, for classical mechanics, continuous energy values are permissible. For example, the atomic weight of iron is 55.85 amu/atom, or 55.85 g/mol. “A” may be expressed in terms of atomic mass units (on an atomic basis), or the mass per mole of atoms. during the latter part of the nineteenth century 质质 质质质质 质质质质
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
C h a p t e r 2 / Atomic Structure and Interatomic Bonding Bohr atomic model: An early atomic model, in which electrons are assumed to revolve around the nucleus in discrete orbitals . One early outgrowth of quantum mechanics
Background image of page 6
Image of page 7
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 10/11/2011 for the course ENG 210 taught by Professor Zhang during the Spring '10 term at Tianjin University.

Page1 / 57

chapter 2 - C h a p t e r 2 / Atomic Structure and...

This preview shows document pages 1 - 7. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online