BYU - PHY S 100 - Class Notes - Week 11

Created by: Erica Bassett Elite Notetaker

Schools > Brigham Young University > OTHER > PHY S 100 > BYU - PHY S 100 - Class Notes - Week 11

School: Brigham Young University

Department: OTHER

Course: Physical Science

Professor: Patricia Ackroyd

Term: Spring 2017

Tags: Spectroscopy, Mixtures, structure of atoms, and Chemistry

Name: Chapter 19, Week 11 Notes

Description: atomic, molecular, and network structures; spectroscopy; pure substances and mixtures

Uploaded: 11/06/2017

This preview shows pages 1 - 2 of a 3 page document. to view the rest of the content

Chapter 19: Atoms, Molecules, and Extended-Bonding
Substances
Classifications of Matter: Pure Substances and Mixtures    Pure Substances: Elements and Compounds • A pure substance: chemical matter that has a defined, fixed chemical composition; made up of
repeating building block • Elements: substance made entirely of the same kind of atom (same number of protons in nucleus) • Compounds: matter that contains two or more atoms in a fixed, definite proportion o Ex: Water! Two hydrogen and one oxygen    Mixtures: Blends/Composites, Solutions and Alloys • Mixtures: substances physically mixed together (little chemical bonding involved)   o We see mixtures in nature more than we see pure substances o If it's a mixture of solids, we call it a blend or a composite ▪ Ex: salt and pepper in a bowl o Solutions: mixtures of pure substances, one of which is a liquid that completely dissolves the
other components o Alloys: a solid solution of metals ▪ Ex: wedding rings--often mostly gold, mixed with silver, copper, and zinc


   Structural Organization of Matter *Types of pure substances: atomic matter, molecular matter, and network/extended-bonding
substances* (divided by atomic-level organization)
   Atomic Matter • Group 8A of Periodic Table: elements exist as simple atoms (full electron shell--8) • This group exists naturally as atomic matter    Molecular Matter • Substances that keep molecules regardless of what state they're in o Ex: Water! (Again) Water is made up of two hydrogen and one oxygen--that's true for water
molecules if it's in a solid, liquid, or gas form      Network Matter • Atoms/ions interact strongly with neighboring atoms to form a continuous linked network (not a 1
to 1 atom bonding relationship)

   Chemical Bonds • From lowest to highest melting/boiling temperatures: atomic matter, molecular matter, network
matter • Chemical bond: attractive force keeping atoms within a molecule together AND force keeping
atoms together in network solids   o Covalent: holds molecules together o Metallic and ionic: hold networks together


   Chemical Formulas and Structures • Chemical formula: atomic symbols for elements in a line   o Ex: hydrogen peroxide= H 2 O 2 • Diatomic molecules: molecules that have two atoms of the same kind (dihydrogen….)    Molecular Structure • Method of showing structure: balls show atoms and sticks show connectivity (what the bond looks
like between atoms) o Can have double and triple bonds between atoms, shown by two or three sticks • Families of Molecules o Carbon atoms make a total of four bonds o Nitrogen atoms make a total of three bonds o Oxygen: 2 bonds o Hydrogen: 1 bond o Hydrocarbon family: molecules made up of carbon and hydrogen atoms only   o Organic acids: molecules that have CO 2 H as part of it o Amine group: NH 2 attached to a carbon atom • Geometry of Molecules o Depending on the bonds made, you'll get a different shape per molecule ▪ Ex: carbon makes a pyramid (tetrahedron) shape when it bonds to four other atoms, a
planar shape when bonds with three, and linear shape when bonds to two   o Bond formation: atoms share a pair of electrons per bond    Extended-bonding Substances • Crystals: a solid with a repeating arrangement of molecules or ions; a large pattern of molecules
bonded in solid state


   Examining Structure *Spectroscopy: techniques used to identify elements that make up molecules, examine how they bond
together, and measure the energy of the bonds. *

This is the end of the preview. Please to view the rest of the content