Aim: How to Calculate the Average Atomic Mass?

Slides:

Advertisements

Similar presentations

Reviewing Subatomic Particles

Advertisements

4.3: HOW ATOMS DIFFER ATOMIC NUMBER

Periodic table Groups – Columns down Alkali Metals Alkaline Earth Metals Halogens Noble gases Periods – Rows across Lanthanides Actinides Groups – Columns.

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.

Essential Question: How do atoms of the same element differ?

Components of the Atom Nucleus: Nuclear Forces:

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.

Atomic Structure. What Is An Atom? the smallest particle of an element that retains the chemical properties of that element Can be subdivided into electrons.

Counting Atoms.

Atomic Structure I. Subatomic Particles.

Isotopes Atoms of the same element that different mass numbers

How Atoms Differ.

Unit 2 Review - Section 1 Atomic Structure and Mass.

Average Atomic Mass.

More about isotopes Atomic mass vs average atomic mass or atomic weight.

& 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.

Subatomic Particles. Atomic Particles ParticleChargeMass (kg)Location Electron9.109 x Electron cloud Proton x Nucleus Neutron

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.

Chapter 5 Notes.  The atomic mass of an element is a weighted average mass of the atoms found in nature.  If you were to mass an oxygen atom, would.

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 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.

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.

How Atoms Differ. a. Properties of Subatomic Particles ParticleSymbolLocationRelative Charge Relative mass Actual mass (g) Electron Proton Neutron.

How Atoms Differ.

Atomic Structure. I. Atoms The atom is the basic unit of matter.

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

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

Atomic Structure Chapter 4. Sizing up the Atom O Radii of most atoms: 5 x m to 2 x m O Copper penny contains 2.4 x atoms. The population.

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

Structure of an Atom Atoms are composed of 3 subatomic particles: 1.Protons (p + ) – Positively charged, found in the nucleus, number of protons determines.

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.

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.

Chapter 4 “Atomic Theory and Structure”

Unit 3 Atomic Structure and Periodicity. Dalton’s Atomic Theory 1.All matter is composed of _____________. 2. Atoms of the same element are _______________.

Essential Question: How do atoms of the same element differ?

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.

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

Unit 2: Symbols Say WHAT?.

How Atoms Differ.

ATOMIC STRUCTURE THE NUCLEUS: 1) THE PROTON:

Calculating Atomic Mass

II. Masses of Atoms Mass Number

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

Atomic Structure Subatomic Particles C. Johannesson.

Atomic Structure Opener: How do you calculate atomic mass? SWBAT:

Average Atomic Mass.

ATOMIC STRUCTURE THE NUCLEUS: 1) THE PROTON:

Atomic Structure.

Atomic Structure Chemistry.

Atomic Structure.

Chapter 4 Atomic Structure 4.1 Defining the Atom

Atomic Structure Chemistry.

Section 4.3 – Distinguishing Among Atoms

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

Chapter 4 Atomic Structure 4.1 Defining the Atom

Element properties & isotopes

Chapter 4 Atomic Structure 4.1 Defining the Atom

Distinguishing Among Atoms

Average Atomic Mass.

Ch. 4 - Atomic Structure II. Masses of Atoms Mass Number Isotopes

Aim: How to Calculate the Average Atomic Mass?

Presentation transcript:

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. 2. If an atom has an atomic mass of 34 and the atom has 16 neutrons, how many protons does the atom have?

Isotopes Atoms of the same element (same number of protons) that have differing numbers of neutrons are called isotopes. Isotopes of an element have: Differing Atomic mass # Differing # of neutrons Same atomic # Changing the number of neutrons does not affect the chemical reactivity of the element.

Isotopes Same element Same chemical properties Second one is radioactive

Most elements occur naturally as mixtures of isotopes. Average Atomic mass Most elements occur naturally as mixtures of isotopes. The mass numbers on the periodic table are the weighted average of the most abundant isotopes’ mass numbers.

How to calculate Avg. Atomic Mass To calculate the atomic mass of an element, multiply the mass of each isotope by its natural abundance, expressed as a decimal, and then add the products.

Sample Problem 1 Rubidium has two common isotopes, 85-Rb and 87-Rb. If the abundance of 85-Rb is 72.2% and the abundance of 87Rb is 27.8%, what is the average atomic mass of rubidium?

Isotope % abundance Fraction of abundance mass 85-Rb 72.2% 0.722 85 amu 87-Rb 27.8% 0.278 87 amu 61.37 24.186 +______________ 85.556 amu X = = X

Sample Problem 2 Uranium is used in nuclear reactors and is a rare element on earth. Uranium has three common isotopes. If the abundance of 234U is 0.01%, the abundance of 235U is 0.71%, and the abundance of 238U is 99.28%, what is the average atomic mass of uranium?

Sample Problem 3 Titanium has five common isotopes: 46Ti (8.0%), 47Ti (7.8%), 48Ti (73.4%), 49Ti (5.5%), 50 Ti (5.3%). What is the average atomic mass of titanium?