Atoms: The Building Blocks of MatterUnit 2

Resource for Periodic Table Basics

PTL! (Periodic Table Live)

www.chemeddl.org/resources/ptl)

Introduction to the Atom Modern Atomic Theory Subatomic Particles Isotopes Ions

Essential Standards and objectives:1.1.1 Analyze the structure of atoms, isotopes, and ions.1.1.2 Analyze an atom in terms of the location of electrons.1.1.3Explain the emission of electromagnetic radiation in spectral form in terms

of the Bohr model.1.1.4 Explain the process of radioactive decay using nuclear equations and half-life. 2.2.5 Analyze quantitatively the composition of a substance. (Introduction to moles)

Agenda 2/10:

Purpose: To determine the structure of an atom Warm-up Review:

Isotopes & how they are represented Number & purpose of the subatomic particles

Calculating Average Atomic Mass Moles –

Warm-up (1) Complete “What’s inside of atoms?”

Warm-up (2) Analyze the compounds

CCl₄ Count the number of atoms

of each element

Determine the type of compound

Write its correct name.

Al₂S₃ Count the number of atoms

of each element

Determine the type of compound

Write its correct name.

The Atom: Smallest particle of an element that retains the chemical properties of the element.

Essential Questions:

What is an atom?

What is its structure?

What determines properties of an element?

Review: What is Z? What is A?

Determine the number of protons, neutrons, and electrons.

6

CCarbon

12.011

12

C 6

13

C 6

Occurs 98.89%frequency

Occurs 1.11 % frequency

In Nature,

Review: Average Atomic Mass

Weighted Average Mass of isotopes Based on the percentage of each isotope

present.

Mass Abundance C-12 12.0 x 98.89 = C-13 13.0 x 1.11=

Practice - Worksheet Atomic Number & Isotopes

Correct symbol: A & Z Complete the table Complete the questions.

Atomic Number & Isotope

Practice: - worksheet Find the Average Atomic Mass

Nucleus of each atom is represented Graphic below #4 - explains #5-7

Isotopes: Atomic Number & Mass Number Determine based on the chart – not the PT 2 Isotope notations

Element – A (X-A) A

ZX

Find Average Atomic Mass

Isotopes: Atomic Number & Mass Number

Element Isotope Symbol

Atomic Number Z

Mass Number A

# of protons

# of neutrons

# of electrons

Electrons in an Atom: Review:

What determines the number? Charge? Mass? Location?

Development of the Modern Atomic Model

Here are several models of the atom as they were developed in history:

............ ......

................

Atom: Scanning Tunneling MicroscopeDetect the negative charge of electrons

Bohr - Discovery Education Video

Quantum Model Electron Cloud model of

the atom

Representing atoms with the Bohr model

Representing atoms with the Bohr Model

Bohr Model – Simplified but Useful ModelGroup

1Group

2Groups

2-12Group

13Group

14Group

15Group

16Group

17Group

18

P1

P2

P3

Bohr Model & the Periodic Table Making Conclusions

Compare and Contrast Why are elements placed in a group (column)? Why are elements placed in a period (row?)

Moles Counting Unit in Chemistry

Agenda: Size of Atoms Moles: a counting unit in chemistry

What is a mole? Why do we use moles? Mole calculations

Factor Label Method

Atoms are very, very small particles Too small to see To small to use an optical microscope

Use a scanning tunneling microscope that is able to detect the electron clouds (due to the negative charge of the electrons)

Size of Atoms: DiameterSome estimates

Atoms including the electron cloud 1 x 10⁻¹⁰ meters

Nucleus 1 x 10⁻¹²m

Proton 1 x 10⁻¹³ m (note: mass: 1x 672 x

10⁻²⁴g) Electron

1 x 10⁻¹⁶m

Atoms are so small: 1 x 10⁻¹⁰ metersQuarks to Quasars, Powers of Ten

Review: Scientific Notation:aka: exponents, power of ten, etc.

Positive exponents: 1 x 10⁶ atoms

Negative exponents: 1 x 10⁻⁶ atoms

Multiplying with exponents: (1.5 x 10³ atoms) x ( 4.2 x 10⁶ atoms) (3.4 x 10³ atoms) x (2.0 x 10⁻⁶ atoms)

Dividing with exponents: (1.5 x 10³ atoms) / ( 4.2 x 10⁶ atoms) (3.4 x 10³ atoms) / (2.0 x 10⁻⁶ atoms)

More information: Appendix near the back of the textbook

Moles Counting Unit in Chemistry

Counting – alternative names for numbers

Gross of pencils

and

When we buy these items, how do we determine the amount?

Moles Video: 4+ minutes

http://ed.ted.com/lessons/daniel-dulek-how-big-is-a-mole-not-the-animal-the-other-one

Review: http://ed.ted.com/lessons/daniel-dulek-how-big-is

-a-mole-not-the-animal-the-other-one#review DigDeeper

http://ed.ted.com/lessons/daniel-dulek-how-big-is-a-mole-not-the-animal-the-other-one#digdeeper

The Mole and Avogadro’s Number What is a mole in chemistry?

How much is a mole? - - -

When are moles used?

Moles How are they measured? (Standards)

The amount of substance that contains as many particles as there are in exactly 12 grams of C-12.

The amount of substance that contains Avogadro’s number of particles.

Molar mass – using the Periodic Table

Moles

Why are moles used?

Moles http://

www.youtube.com/watch?v=Qg0Lajwew3A

A mole is a unit - song

http://www.youtube.com/watch?v=U1frmqkNqW0

Salt particle- NaClModel of NaCl as an ionic compound

Each salt particle in this photomicrographwould require the model to be multiplied by 10⁶ or more

Formula Unit: NaClRepresents the repeating units that make up an ionic compound Such as NaCl, CaCl, Al₂O₃

New Term

Amounts: How can we determine the amount of salt particles in this picture?

Mole Conversions (Factor Label Method)

Moles ↔ Grams3.5 moles of He = ? Grams

40 grams of He = ? Moles

Molar mass: 1 mole of He = ? Grams

Mole Conversions Moles ↔ Particles (atoms, molecules, compounds, etc.)

3.5 moles of He = ? Atoms

12.04 x 10²³ atoms of He = ? Moles

1 mole = atoms

Review scientific notation

Mole Conversions Moles ↔ Volume of Gas (at STP)

3.5 moles of He = ? Liters

100 Liters of He = ? Moles

1 mole of a gas = Liters

Mole Flow Chart

Mole

Practice problems: Moles and Mass What is the mass of 0.5 moles of S?

How many grams is equivalent to 0.137 moles of Fe?

4.63 mol P = ? grams P

Practice problems How many moles are in 84.3 grams of Si?

50 grams of Ne = ? moles of Ne

Mole and Atom Conversions How many atoms of Al are in 2.5 moles?

How many atoms of Ag are in 0.26 moles?

How many atoms of He are in 0.0023 moles?

Mole and Atom Conversion How many moles of P contains 1.0 x 10²³

atoms?

How many moles of Au are in 2.8 x 10²º atoms?

Moles, Moles, Moles LabSample in a jar

Mass Moles Atoms

1 mole = ? grams 1 mole = ? atoms

Molar Mass of Compounds NaCl CH₄

H₂O CO₂

MgCl₂ MgO

Review types of compounds & names

Mole Conversion of Compounds How many grams are in 5 moles of CO₂?

How many atoms are in 5 moles of CO₂?

How many liters are in 5 moles of CO₂?

A Mole is a Number

Review

Carbon has 6 protons