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.

Slides:

Advertisements

Similar presentations

Isotope Notation Isotope Notation uses a symbol to convey information about an isotope of a particular element. 23 Na 11.

Advertisements

4.3: HOW ATOMS DIFFER ATOMIC NUMBER

Atomic Number, Mass Number, Atomic Mass and Isotopes Mrs. Coyle Chemistry.

Atomic Structure Section The Nucleus Nucleus- contains most of the mass of an atom – Protons & Neutrons contains most of an atom’s mass – Electrons-

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.

Atomic Number What makes one element different from another? 4.3

Atomic Structure Nucleus – contains protons and neutrons

Unit 3: Atomic Structure Atomic Number, Mass Number, and Isotopes.

Atomic Mass & Number Isotopes The Periodic Table.

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

{ Distinguishing Among Atoms The Atom.  Atoms are composed of protons, neutrons, and electrons.  Protons and neutrons make up the nucleus.  Electrons.

Isotopes and Mass Number. Atomic Number The number of protons in each atom identifies it as an atom of a particular element Each atom has a unique number.

Bellringer 10/01/12 How many protons, neutrons and electrons are in U-235 and Pu-244?

Atomic Structure I. Subatomic Particles.

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

Section 2: The Structure of Atoms

Isotopes Atoms of the same element that different mass numbers

Ions An atom that carries an electrical charge is called an ion If the atom loses electrons, the atom becomes positively charged (because the number of.

The Atom What is it made of???. Protons  Positively charged  Mass = 1 amu = 1.67 x grams  Located in the nucleus  Gives an atoms its identity.

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

How atoms differ. Mass Number The sum of the protons and neutrons BUT…Why is it not an even number??

Average Atomic Mass.

Masses of Atoms Chapter 19-2 Pages

& 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.

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

Chapter 4.3 Distinguishing Among Atoms

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.

Do Now: If a student’s grade is weighted per the table below, what would their grade be? WeightAverage Tests50%80 Classwork30%95 Homework20%85.

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)

Atomic Mass and Isotopes. Review Quiz ParticleChargeMassLocationSymbol Electron Proton Neutron.

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.

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.

Atomic Structure What are atoms made of? How are atoms put together? What are Elements? Isotopes?

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.

Parts of the Atom: Properties  Protons: –Positive charge –Located in nucleus –Mass = 1 amu (Atomic Mass Unit)  Neutrons –No charge (neutral) –Inside.

Notes on Isotopes Remember Protons are (+) and Electrons are (-). Neutrons were the last subatomic particles to be discovered because they have no electrical.

Chapter 3 Isotopes Part II. Atoms Nucleus is center core. Nucleus is center core. Nucleus is made of Protons & Neutrons. Nucleus is made of Protons &

Distinguishing among Atoms

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

Neutrons and Isotopes. NEUTRONS AND ISOTOPES Unlike the number of protons, the neutrons in the nucleus of atoms of the same element can vary. Atoms of.

Ch. 3-3a Distinguishing and Counting Atoms. POINT > Define Atomic Number POINT > Define Mass Number POINT > Describe and identify isotopes POINT > Determine.

Isotopes. What is an isotope? Not all atoms of an element are identical. Some elements have isotopes. Isotopes (iso means “same”) are atoms with the same.

UNIT 3: DAY 1 AND DAY 3 ATOMIC STRUCTURE. ATOM, ELEMENTS, AND COMPOUNDS Atoms are the smallest unit of matter In classification, all atoms are elements.

Concept Check 2.1 Atomic Size

1 The Atom Atomic Number and Mass Number Isotopes.

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

Lesson 24: Isotopes An element can be identified by the # of protons it has # of neutrons can vary Neutrons add to the mass of the atom, but do not change.

Calculating Atomic Mass

The Modern View of Atomic Structure

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 Mass

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

A B 21085At Fe Mo 5827Co 3216S Pb4+ Symbol

Section 1 Structure of the atom and cells on the periodic table

Foldables: Atoms Terms.

Mass of Individual Atoms

How Atoms Differ Chp 4.

Atomic Structure Chemistry.

Section 2.4 Atomic Weights.

Atomic Math Calculations

More about Elements.

Presentation transcript:

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 masses are not whole numbers Calculate the number of electrons, protons, and neutrons in an atom given its mass number and atomic number

Atomic Number References the number of protons in the nucleus of an atom of a particular element Every element has a unique atomic number Atomic Number = # of protons = # of electrons IN A NEUTRAL ATOM!!!

Question If Pb has an atomic number of 82, how many protons are in the nucleus of every atom of Pb? How many electrons must be orbiting the nucleus of every neutral Pb atom?

Mass Number Total number of protons plus neutrons in the nucleus of an atom of an element Uses the number of neutrons in the most abundant form of the element

How many protons? How many electrons? How many neutrons?

Isotopes Atoms with identical atomic numbers but different mass numbers Number of Neutrons = Mass Number - # of protons

Mass of the Atom Expressed in the atomic mass unit (amu) 1 amu = x g 1 g = x amu

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.

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

Solution Average atomic weight = (0.7578)( amu) + (0.2422)( amu) = amu