Average Atomic Mass If there are 2 naturally occurring isotopes of

Slides:

Advertisements

Similar presentations

Average Atomic Mass & % Abundance

Advertisements

Average Atomic Mass Practice

Chapter 11B Notes Determining Isotope Masses. Intro What is the mass of an atom with 6 protons and 6 neutrons? 12 What is the mass of an atom with 6 protons.

ISOTOPIC NOTATION isotopes are atoms with the same number of protons but different number of neutrons A Z X A = mass number (the total number of protons.

What is average atomic mass?

Average Atomic Mass.

Relative atomic mass Atoms are too small to be weighed individually, even with the best balance! We can, however, compare the masses of different atoms.

Average Atomic Mass. Masses of Atoms A scale designed for atoms gives their small atomic masses in atomic mass units (amu) An atom of 12 C was assigned.

Average Atomic Mass. Average Atomic Mass – the weighted average of the masses of the isotopes of an element Every element is composed of several naturally.

Examples: Average Atomic Mass. Example Chlorine exists as a mixture of % chlorine-35 and % chlorine-37. Determine the average atomic mass.

ISOTOPES and RELATIVE ABUNDANCE What is an isotope? What is relative abundance?

Atomic Mass. Isotopes Reminder Yesterday we learned that the mass of all atoms of a certain element are not always the same –Some atoms may have more.

Isotopes Atoms of the same element that different mass numbers

Unit 3: Atomic Theory & Structure Section 2 – Distinguishing Among Atoms.

Date: Objective Background Lab 8 The Atomic Mass of “Boltium”

Average Atomic Mass.

& Average Atomic Mass  Atoms with the same number of protons (they are the same element) but different number of neutrons.

Average Atomic Mass A different kind of average…

 Atomic Number- the number of protons in the nucleus of an atom of that element  Ex: Hydrogen atoms have only one proton in the nucleus, so the atomic.

Friday October 1, 2015 TO DO RIGHT NOW: 1.Get out your HW and PT 2.Copy words on page 42 3.Update your table of contents HOMEWORK Due Monday- Isotope Worksheet.

Using Isotope Data to Find a Weighted Average.  Each isotope will have two values associated with it.  Mass of Isotope  Percent Abundance (% found.

Atomic Mass The Atomic Mass of Candium Lab. Atomic Mass This is the weighted average mass of the atoms in nature of that element A weighted avg mass reflects.

Atomic Mass. Masses in amu Only carbon-12 has an atomic mass exactly equal to its mass # One atomic mass unit (amu) is defined as 1/12 the mass of a carbon-12.

Isotopic Abundance SCH 3U. Atomic Mass The mass of an atom (protons, neutrons, electrons) Relative Atomic Mass: An element’s atomic mass relative to the.

Section 4.3 How atoms differ. Atomic Number Represents three things in a neutral atom: 1. What element it is 2. The number of protons in each atom 3.

 The weighted average of its naturally occurring isotopes. Chemical Name Atomic # Chemical Symbol Atomic Mass (Average Atomic Mass)

Average atomic Mass. What does the atomic mass tell us on the Periodic table?

Chapter 3 Average Atomic Mass. Section 3 Counting Atoms Relative Atomic Masses The standard used by scientists to compare units of atomic mass is the.

Average Atomic Mass If there are 2 naturally occurring isotopes of Neon including Ne-20 and Ne-22. then the average mass of Neon atoms should be ___ amu.

Average Atomic Mass. Relative Atomic Masses  Masses of atoms (in grams) are very small, so for convenience we use relative masses.  Carbon-12 is our.

Determining Average Atomic Mass

What is average atomic mass?

Average Atomic Mass What is average atomic mass? Average atomic mass is the weighted average of the atomic masses of the naturally occurring isotopes of.

Average Mass Activity Find the average mass of all the spheres in the tray. You may: -Make no more than 3 mass measurements. -Mass only 1 sphere at a time.

Chapter 4 AVERAGE ATOMIC MASS. Atomic Mass… n The weighted average of the masses of all the naturally occurring isotopes of that element. n Is not a whole.

Atomic Structure. Subatomic Particles In the nucleus: Protons Mass  1 amu Charge = +1 Neutrons Mass  1 amu Charge = 0 In the electron cloud: Electrons.

Average Atomic Mass ► Average Atomic Mass – the weighted average of the masses of the isotopes of an element ► Every element is composed of several naturally.

Average Atomic Mass!!!. Copper is made of two isotopes. Copper- 63 is 69.17% abundant and it has a mass of amu. Copper-65 is 30.83% abundant and.

Average Atomic Mass Practice

Lab 9 The Atomic Mass of “Boltium” Purpose Calculate the atomic mass of “Boltium” Background The atomic mass of any element is a weighted average of all.

Warm-Up -Write the correct Nuclide Symbol for the following elements: *19 p+, 20 n *82 e-, 125n *Mass # 238, neutrons= 146.

Calculating Atomic Mass

Average Atomic Mass In nature, most elements are a mixture of different isotopes The mass of a sample of an element is a weighted average of all the isotopes.

Calculating Average Atomic Mass

Calculating Average Mass

What is average atomic mass?

What is average atomic mass?

Average atomic Mass.

Estimating the Mass Number:

Average Atomic Mass.

Unit 2: Atomic Theory & Structure

How to calculate it! Average Atomic Mass.

ISOTOPIC NOTATION isotopes are atoms with the same number of protons but different number of neutrons A Z X A = mass number (the total number of protons.

Unit 2: Atomic Theory & Structure

Standard Atomic Weights on Periodic Table (red numbers) are found through the terrestrial (Sol III) relative abundances of the masses (in amu) of the isotopes.

Average Atomic Mass.

Calculating Average Atomic Mass

Average Atomic Mass.

Mass Spectrometer.

Section 2.4 Atomic Weights.

Standard Atomic Weights on Periodic Table (red numbers) are found through the terrestrial (Sol III) relative abundances of the masses (in amu) of the isotopes.

Atomic Symbols = = mass # atomic # protons + neutrons protons

Calculating Average Atomic Mass

Isotopes Atoms of the same element with a different number of neutrons

Atomic Math Calculations

Structure of the Nucleus

Distinguishing Among Atoms

Average Atomic Mass.

Chemistry Chapter 3 Section 3

Presentation transcript:

Average Atomic Mass If there are 2 naturally occurring isotopes of Neon including Ne-20 and Ne-22. then the average mass of Neon atoms should be ___ amu. Why does the PT lists it as 20.18 amu? Calculated as a weighted average of atoms in a sample of naturally occurring isotopes.

63Cu is 69% abundant 65Cu is 31% abundant Average Atomic Mass A weighted average atomic mass is calculated from both the masses of each isotope and the relative abundance (%) of each isotope. 63Cu is 69% abundant 65Cu is 31% abundant To which will the average mass be closer, 63 or 65?

= 63.55 Calculating Average Atomic Mass copper-63 has a mass of 62.93 amu and natural abundance of 69.15% copper-65 has a mass of 64.93 amu and has a natural abundance of 30.85% Calculating Average Atomic Mass Avg. Mass = (Mass1)(%) + (Mass2)(%) … = (62.93)(0.6915) + (64.93)(0.3085) = 63.55

neon-20 neon-22 Which isotope is in greater relative abundance in natural samples of neon? because… the weighted average atomic mass of neon from the PT is 20.18 amu. 90% - 20, <1% - 21, 9% - 22

= 32.2 Avg. = (M1)(%) + (M2)(%) = (32)(0.900) + (34)(0.100) Quick Quiz! 1. If an unusually selected sample of sulfur contained 90.0% sulfur-32 and 10.0% sulfur-34, what would be its average atomic mass? 32.2 amu 32.9 amu 33.5 amu 34.2 amu Avg. = (M1)(%) + (M2)(%) = (32)(0.900) + (34)(0.100) = 32.2