Determining Average Atomic Mass

Slides:

Advertisements

Similar presentations

4.3: HOW ATOMS DIFFER ATOMIC NUMBER

Advertisements

Average Atomic Mass & % Abundance

Average Atomic Mass. How much does an atom weigh?  Protons & Neutrons:  1.67 X gram  Electrons:  9.10 X gram  To avoid working with.

Calculating Average Atomic Mass. Introduction The value for atomic mass for a particular element is the average atomic mass. Each sample of an element.

AIM: HOW TO CALCULATE THE AVERAGE ATOMIC MASS? DO NOW:1. WHAT ARE THE 3 SUBATOMIC PARTICLES OF AN ATOM? LIST THE THREE SUBATOMIC PARTICLES AND THEIR CHARGE.

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.

OF PROTONS, NEUTRONS AND ELECTRONS IN AN ATOM

Average Atomic Mass.

 Protons, neutrons, electrons too  Make up the atoms all around you!

1 Average Atomic Mass Chemistry Notes. 2 Relative Atomic Mass  Masses of atoms expressed in grams are very small, for example: One atom of Oxygen-16.

 Definition: Atoms of the same element that differ in their # of neutrons; therefore, they have different mass numbers.  Nearly every element has isotopes!

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.

 Each element on the periodic table has an isotope.  What make an element have different isotopes?  There are 2 different isotopes of iron  Find the.

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.

Mass Number Atomic Number equals the # of... NUCLEUS ELECTRONS PROTONS NEUTRONS NEGATIVE CHARGE POSITIVE CHARGE NEUTRAL CHARGE ATOM.

Isotopes Atoms of the same element that different mass numbers

Number of Protons = Number of Electrons Number of Protons = Atomic Number Atomic Mass = Protons + Neutrons.

Average Atomic Mass The weighted average of the masses of all the naturally occurring isotopes of an element.

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.

 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.

Isotopes Atoms of the same element with different mass numbers. Mass # Atomic # Nuclear symbol: Hyphen notation: carbon-12 Courtesy Christy Johannesson.

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

Calculating the Average Atomic Mass. Steps for Calculating Average Atomic Mass (When given percentages of each isotope and each isotopes mass) 1. Convert.

Ch. 3 - Atomic Structure II. Masses of Atoms (p.75-80)  Mass Number  Isotopes  Relative Atomic Mass  Average Atomic Mass.

…AND THE AVERAGE ATOMIC MASS Isotopes. PG 88 GENERAL- ATOMS OF THE SAME ELEMENT BUT HAVE DIFFERENT AMOUNTS OF NEUTRONS IN THE NUCLEUS PAGE 54 PRE AP ATOMS.

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.

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

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 How to use relative abundance to calculate average atomic mass.

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.

Average Atomic Mass.   atomic masses reported in periodic table represent: weighted average of masses of all naturally occurring isotopes of an element.

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.

Atomic Mass. Atomic mass Most of the mass of an atom is in the nucleus. Most of the mass of an atom is in the nucleus. The nucleus is where all of the.

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.

Protons, Neutrons, and Electrons

Isotopic Abundance Pages Thinking question Why are there decimal places for atomic masses on the periodic table if protons and neutrons have amu.

Isotope Atoms that have the same number of p +, but different numbers of n o.

Average atomic mass of lithium isotopeabundanceatomic mass Li-67.49% amu Li % amu.

WEIGHTED AVERAGE MASS NUMBER: 1)The mass number on the periodic table is calculated from the weighted average of the most abundant isotopes. 2) Abundance.

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.

This is the solution for carbon: (12) (0.9890) + (13) (0.0110) = amu mass number percent abundance % % Recall!!! carbon:

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.

Atomic Mass Mrs. Cook. Atomic Mass - The average relative mass of all naturally occurring isotopes of an element. relative mass – The mass of one object.

Daily Science Who discovered the electron and how did he discover it? What was his model called? What tells you the number of p + an element has? Write.

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

Aim: How to Calculate the Average Atomic Mass?

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

Estimating the Mass Number:

Average Atomic Mass.

Atomic Structure.

Isotopes and Calculating Atomic Mass

Atomic Structure.

Average Atomic Mass.

Average Atomic Mass.

Section 2.4 Atomic Weights.

0:56 0:55 0:54 0:53 0:57 0:58 1:02 1:01 1:00 0:59 0:52 0:51 0:44 0:43 0:42 0:41 0:45 0:46 0:50 0:49 0:48 0:47 1:03 1:04 1:19 1:18 1:17 1:16 1:20 1:21 1:25.

Calculating Average Atomic Mass

Average Atomic Mass.

Average Atomic Mass.

Aim: How to Calculate the Average Atomic Mass?

Atomic Number and Mass Number

Chemistry Chapter 3 Section 3

Presentation transcript:

Determining Average Atomic Mass Chemistry Unit One

Atomic Mass Unit (amu) 1/12 of the mass of a Carbon-12 atom It is used to describe the atomic masses of individual atoms and compounds Masses of all atoms are determined relative to the Carbon-12 atom

Average Atomic Mass The weighted average of the atomic masses of each of the isotopes of an element Units are amu These values can be found on the periodic table

Determining Average Atomic Mass Isotope %abundance Atomic mass 1H 99.985% 1.007825 amu 2H 0.015% 2.014102 amu Step 1: Obtain the natural abundance and atomic mass of each isotope of an element.

Determining Average Atomic Mass Isotope abundance Atomic mass 1H 0.99985 1.007825 amu 2H 0.00015 2.014102 amu Step 2: Convert the abundances from percents to decimals.

Determining Average Atomic Mass Isotope abundance Atomic mass 1H 0.99985 X 1.007825 amu = 1.00767 amu 2H 0.00015 X 2.014102 amu = 0.00030 amu Step 3: Multiply the abundances and atomic mass for each isotope

Determining Average Atomic Mass Isotope abundance Atomic mass 1H 0.99985 X 1.007825 amu = 1.00767 amu 2H 0.00015 X 2.014102 amu = 0.00030 amu 1.00797 amu Step 4: Add the results. This sum is the average atomic mass.

Find the average atomic mass of Copper Isotope %abundance Atomic mass 63Cu 69.17% 62.929599 amu 64Cu 30.83% 64.927793 amu 63.55 amu

Find the average atomic mass of Oxygen Isotope %abundance Atomic mass 16O 99.762% 15.994915 amu 17O 0.038% 16.999131 amu 18O 0.200% 17.999160 amu 15.999 amu

Find the average atomic mass of Uranium Isotope %abundance Atomic mass 234U 0.005% 234.040947 amu 235U 0.720% 235.043924 amu 238U 99.275% 238.050784 amu 238.03 amu