ch2notes - 2010 Donald L.Siegel All rights reserved Chapter...

Info iconThis preview shows pages 1–12. Sign up to view the full content.

View Full Document Right Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 2010 Donald L.Siegel All rights reserved Chapter 2 Chapter 2 Atoms, Molecules, and Ions 2010 Donald L.Siegel All rights reserved Conservation of Mass and Conservation of Mass and Law of Definite Proportions Law of Definite Proportions W Matter can neither be created nor destroyed Kinds of matter (elements) cant even be changed Arrangement can W The basic units of matter can only combine in simple ratios W Mass percentage is one way to express the ratio 2010 Donald L.Siegel All rights reserved Laws of Composition Laws of Composition W Constant Composition All samples of the same substance have the same composition Water is water everywhere Can express composition as %s W Multiple Proportions Only certain ratios are possible Example Ammonia: 17.6% Hydrogen, 82.4% Nitrogen Ammonia: 17.6% Hydrogen, 82.4% Nitrogen Hydrazine: 12.5% Hydrogen, 87.5% Nitrogen Hydrazine: 12.5% Hydrogen, 87.5% Nitrogen 2010 Donald L.Siegel All rights reserved Atomic Theory Atomic Theory W Matter comes in fundamental units called atoms All atoms of a given element are identical W Atoms cannot be divided Simple ratios 2010 Donald L.Siegel All rights reserved Atomic Weights Atomic Weights W By determining the combining masses of elements, we can organize them by their relative masses Origins of atomic mass (sometimes called atomic weight) 2010 Donald L.Siegel All rights reserved The Nuclear atom The Nuclear atom W Atoms are composed of protons, neutrons and electrons Protons and neutrons located in a very dense nucleus Electrons are found outside the nucleus W Z - nuclear charge, measures the number of protons W A - nuclear mass, measures the number of neutrons plus protons 2010 Donald L.Siegel All rights reserved Subatomic particles Subatomic particles W Most of the mass of the atom is found in the nucleus 2010 Donald L.Siegel All rights reserved Elements and atoms Elements and atoms W An element is a substance that cannot be broken down into anything simpler by chemical means. W All matter is composed of atoms of various types. An element is composed of atoms of the same type W Element names and symbols 2010 Donald L.Siegel All rights reserved Isotopes Isotopes W Different varieties of the same element W Which element is determined by Z, the number of protons W Which isotope is which is determined by A W All isotopes of the same element have very similar chemical properties 2010 Donald L.Siegel All rights reserved Isotopic mass and Natural Abundance Isotopic mass and Natural Abundance W Atomic mass is the average of the isotopic masses W A = f i a i f i is the natural abundance of isotope i a i is the mass of isotope i W Need another equation 1 = f i 2010 Donald L.Siegel All rights reserved Example Example W Boron has 2 isotopes: 10 B with mass 10.0129u 11 B with mass 11.0093u W What is the natural abundance of 10 B?...
View Full Document

This note was uploaded on 03/08/2011 for the course CHEM 161 taught by Professor Vacillian during the Fall '08 term at Rutgers.

Page1 / 43

ch2notes - 2010 Donald L.Siegel All rights reserved Chapter...

This preview shows document pages 1 - 12. Sign up to view the full document.

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