Section 2.4 Atomic Weights.

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.

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.

What is average atomic mass?

Average Atomic Mass.

Atomic Calculations and Mass Spectrometry Quantum Orbital Video.

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.

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

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.

Average Atomic Mass.

Isotopes  Atoms with the same number of protons but different numbers of neutrons  Ex) Carbon 12 vs. Carbon 14  These atoms have a different mass 

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

Unit 3: Atomic Structure Atomic Mass Units (amu) and Calculating Atomic Mass.

 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.

1 Atomic Mass The atomic mass of an element is listed below the symbol of each element on the periodic table. gives the mass of an “average” atom of each.

4.7 Atomic Mass Even the largest atoms have very small masses (Fluorine – x ) Even the largest atoms have very small masses (Fluorine –

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

Section 4.3 How Atoms Differ. Objectives Explain the role of atomic number in determining the identity of an atom Define an isotope and explain why atomic.

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.

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

Isotopes. The Nucleus  The number of protons in the nucleus of an atom is unique to each type of element  BUT, the nuclei of the same type of 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.

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.

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.

Comparing Atomic Mass and Mass Numbers Atomic Mass Mass Number The mass number is the total amount of protons and neutrons in an atom. An atom of an element.

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.

1 The Atom Atomic Number and Mass Number Isotopes.

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.

Same Element Different Atom- Isotopes All atoms of a particular element are not exactly alike. Some elements have atoms with different masses (isotopes)

Reminders & Daily Schedule

Average Atomic Mass & Abundance

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.

Learning Check Naturally occurring carbon consists of three isotopes: Carbon-13, Carbon-14, and Carbon-15. State the number of protons, neutrons, and.

Atomic Calculations and Mass Spectrometry

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.

Mass of Individual Atoms

Average Atomic Mass.

Atomic Structure Chemistry.

Average Atomic Mass If there are 2 naturally occurring isotopes of

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.

Element properties & isotopes

Average Atomic Mass.

Average Atomic Mass.

Atomic Mass Na The atomic mass of an element

Chemistry Chapter 3 Section 3

Presentation transcript:

Section 2.4 Atomic Weights

Atomic Weight Determined by average atomic masses of the isotopes of an element Atomic Weight = Sum of multiplying the abundance of each isotope by its atomic mass

Isotopes: There are 23 known isotopes of krypton, 6 stable and 17 unstable. Natural krypton contains the 6 stable isotopes.

Sample Atomic Weight Problem Naturally occurring chlorine is 75.78% 35Cl, which has an atomic mass of 34.969 amu, and 24.22% 37Cl, which has an atomic mass of 36.966 amu. Calculate the average atomic weight of chlorine.

Solution Average atomic weight = (0.7578)(34.969 amu) + (0.2422)(36.966 amu) = 35.45 amu Don’t forget your Sig Figs!!!