Presentation is loading. Please wait.

Presentation is loading. Please wait.

The Atom Elements! Elements! Elements!. Objectives Atomic Structure The Atomic Theory and History Atomic Math Atomic Structure The Atomic Theory and History.

Similar presentations


Presentation on theme: "The Atom Elements! Elements! Elements!. Objectives Atomic Structure The Atomic Theory and History Atomic Math Atomic Structure The Atomic Theory and History."— Presentation transcript:

1 The Atom Elements! Elements! Elements!

2 Objectives Atomic Structure The Atomic Theory and History Atomic Math Atomic Structure The Atomic Theory and History Atomic Math

3 Element Quizzes In order to strengthen your familiarity with elements, you will be required to take element quizzes.

4 Element Wanted Poster To demonstrate you knowledge of the concepts we will cover this six weeks. You will be expected to create a poster containing information about an element in the form of a WANTED poster.

5 Atomic Structure

6 Atoms are the building blocks of matter. Atoms make up elements – in fact everything is made of atoms! There are 92 elements that occur naturally on Earth and about a dozen more that are man-made. All the elements can be found on the Periodic Table of the Elements. Atoms are mostly empty space. Atoms are the building blocks of matter. Atoms make up elements – in fact everything is made of atoms! There are 92 elements that occur naturally on Earth and about a dozen more that are man-made. All the elements can be found on the Periodic Table of the Elements. Atoms are mostly empty space.

7 There are two regions in the atom: Nucleus Most of the mass Has a positive charge Electron Cloud Most of volume/space Has a negative charge Nucleus Most of the mass Has a positive charge Electron Cloud Most of volume/space Has a negative charge

8 Each region has specific subatomic particles Nucleus Protons p + Have a positive charge Mass = 1 amu Discovered by E. Rutherford Neutrons n 0 Have a neutral or no charge Mass = 1 amu Discovered by J. ChadwickNucleus Protons p + Have a positive charge Mass = 1 amu Discovered by E. Rutherford Neutrons n 0 Have a neutral or no charge Mass = 1 amu Discovered by J. Chadwick Electron Cloud Electrons e - Have a negative charge Mass = 0 amu Discovered by J.J. Thomson

9 Lets Check for Understanding What are the two regions of the atom? Which one is most of the mass of the atom? Which one is most of the volume? What are the subatomic particles and where are they found? What are the two regions of the atom? Which one is most of the mass of the atom? Which one is most of the volume? What are the subatomic particles and where are they found?

10 The Atomic Theory and History

11 Democritus and atomos Democritus was an ancient Greek philosopher (he lived around 400 B.C.) who believed that matter could not be divided into smaller and smaller pieces forever and ever. He called the smallest pieces of matter atomos which means indivisible or unbreakable.

12 John Dalton A nineteenth century scientist who also believed that matter was made up of atoms. He coined the term atom from the Greek word atomos..

13 In this first modern atomic theory he stated: 1. Atoms are small, indivisible particles that are the building blocks of matter. (He viewed them as solid spheres.) 2. Atoms can be physically mixed together to form mixtures. 3. Atoms cannot be changed into another element through chemical reactions. 1. Atoms are small, indivisible particles that are the building blocks of matter. (He viewed them as solid spheres.) 2. Atoms can be physically mixed together to form mixtures. 3. Atoms cannot be changed into another element through chemical reactions.

14 In this first modern atomic theory he stated: 4. Atoms can be combined or rearranged in whole number ratios to form compounds through chemical reactions. 5. All atoms of a particular element are exactly the same; atoms of different elements are different 4. Atoms can be combined or rearranged in whole number ratios to form compounds through chemical reactions. 5. All atoms of a particular element are exactly the same; atoms of different elements are different

15 Check for Understanding What did Democritus believe? Who expanded on Democritus beliefs and how? Name the points of the Modern Atomic Theory. What did Democritus believe? Who expanded on Democritus beliefs and how? Name the points of the Modern Atomic Theory.

16 Atomic Math

17 Lets Review From previous slides you have learned that all elements/atoms are listed on what? The Periodic Table of Elements From previous slides you have learned that all elements/atoms are listed on what? The Periodic Table of Elements

18 1 H Hydrogen Atomic Number Element Symbol Atomic Mass Element Name Atomic Number Element Symbol Atomic Mass Element Name

19 1 H Hydrogen Atomic Number The whole number on the chart Equivalent to the number of protons and electrons if there is no charge. Atomic Number The whole number on the chart Equivalent to the number of protons and electrons if there is no charge.

20 1 H Hydrogen Atomic Mass The decimal number on the chart. Average number of different masses of naturally occurring isotopes of an element. Units: may be in grams or atomic mass units (amu) amu = defined as exactly 1/12 th the mass of a carbon-12 atom Atomic Mass The decimal number on the chart. Average number of different masses of naturally occurring isotopes of an element. Units: may be in grams or atomic mass units (amu) amu = defined as exactly 1/12 th the mass of a carbon-12 atom

21 1 H Hydrogen Mass Number The atomic mass rounded to the nearest whole number. Equivalent to the number of protons plus the number of neutrons. Mass Number The atomic mass rounded to the nearest whole number. Equivalent to the number of protons plus the number of neutrons.

22 Atomic Math Overview # of p + = Atomic Number # of n = Mass Number - # of p 0 # of e - (no charge) = # of p + # of p + = Atomic Number # of n = Mass Number - # of p 0 # of e - (no charge) = # of p +

23 Elemental Symbols A- Mass Number Z- Atomic Number X- Element Symbol A- Mass Number Z- Atomic Number X- Element Symbol X A Z

24 Fe Try this one on your own Element Protons Neutrons Electrons Atomic # Mass # Charge Iron

25 How many protons and neutrons are in one atom of 3 7 Li? How many protons and neutrons are in one atom of W? How many protons and neutrons are in one atom of 3 7 Li? How many protons and neutrons are in one atom of W? 3 protons and 4 neutrons 74 protons and 110 neutrons

26 Isotopes

27 Atoms that have the same number of protons and electrons but different numbers of neutrons Isotopes have different mass numbers because of the differing numbers of neutrons Atoms that have the same number of protons and electrons but different numbers of neutrons Isotopes have different mass numbers because of the differing numbers of neutrons

28 Isotope names are the atom name and mass number hyphenated Isotopes with practical uses: carbon-14 ~ archaeological carbon dating americium-241 ~ smoke alarms cobalt-60 ~ treatment of cancer Isotope names are the atom name and mass number hyphenated Isotopes with practical uses: carbon-14 ~ archaeological carbon dating americium-241 ~ smoke alarms cobalt-60 ~ treatment of cancer

29 Isotopes In nature, most elements occurs as a mixture of two or more isotopes. Each isotope of an element has a fixed mass and a natural percent abundance. Example: Carbon has two isotopes. Both have 6 protons carbon-12: six neutrons (C-12) carbon-13: seven neutrons (C-13) In nature, most elements occurs as a mixture of two or more isotopes. Each isotope of an element has a fixed mass and a natural percent abundance. Example: Carbon has two isotopes. Both have 6 protons carbon-12: six neutrons (C-12) carbon-13: seven neutrons (C-13)

30 Isotopes & Atomic Mass Atomic mass of an element is a weighted average of the masses of its isotopes. You can calculate atomic mass based on relative abundance. You will need the : mass of each isotope natural percent abundance of each isotope Atomic mass of an element is a weighted average of the masses of its isotopes. You can calculate atomic mass based on relative abundance. You will need the : mass of each isotope natural percent abundance of each isotope

31 Calculating Atomic Mass To calculate the atomic mass of an element: Multiply the atomic mass of each isotope by its abundance expressed as a decimal Add the results for all isotopes To calculate the atomic mass of an element: Multiply the atomic mass of each isotope by its abundance expressed as a decimal Add the results for all isotopes

32 Example Magnesium occurs in nature in three isotopic forms: atomic mass Mg-24 (78.70% abundance) amu Mg-25 (10.13% abundance) amu Mg-26 (11.17% abundance) amu Calculate the atomic mass of magnesium for these data. Magnesium occurs in nature in three isotopic forms: atomic mass Mg-24 (78.70% abundance) amu Mg-25 (10.13% abundance) amu Mg-26 (11.17% abundance) amu Calculate the atomic mass of magnesium for these data.

33 Calculation: For Mg-24: amu x = amu For Mg-25: amu x = amu For Mg-26: amu x = amu atomic mass = amu For Mg-24: amu x = amu For Mg-25: amu x = amu For Mg-26: amu x = amu atomic mass = amu

34 Ions

35 Atoms are electrically neutral: # protons (+) = # electrons (-) Atoms may lose or gain electrons when they react with atoms of other substances. They become electrically charged particles called ions. Atoms are electrically neutral: # protons (+) = # electrons (-) Atoms may lose or gain electrons when they react with atoms of other substances. They become electrically charged particles called ions.

36 Two Types of Ions Cations Loss of electrons Now has more protons than electrons Anions Gain of electrons Now has more electrons than protons *Denoted by charge in upper right of symbol. Cations Loss of electrons Now has more protons than electrons Anions Gain of electrons Now has more electrons than protons *Denoted by charge in upper right of symbol.

37 X AY Z A- Mass Number Z- Atomic Number Y- Charge X- Element Symbol Atomic Math

38 Denoting Ion Charges Ion charges – the sign follows after the number To calculate ion charges: # protons - #electrons Example: An atom of lithium loses 2 electrons (lithium normally has 3 e-). It now is an ion with 2 more protons than electrons. (Ion charge: 3 protons – 1 electron = 2 + ) Overall, this lithium ion has a positive 2 charge. Write this using the elemental symbol: Li 2+ We can now add the atomic number and mass number to the symbol: 7 3 Li 2+

39 Atomic Math Breakdown Cheat Chart # of p + = Atomic Number # of n = Mass Number - # of p # of e - (no charge) = # of p + # of e - (w/ charge) = # of p + - charge

40 Fe Atomic Math Element Protons Neutrons Electrons Atomic # Mass # Charge Iron

41 Practice Problems

42 Fe Try this one on your own Element Protons Neutrons Electrons Atomic # Mass # Charge Iron

43 How many protons, neutrons, and electrons are in one atom of 3 7 Li 1+ ? How many protons, neutrons, and electrons are in one atom of W 3+ ? How many protons, neutrons, and electrons are in one atom of 3 7 Li 1+ ? How many protons, neutrons, and electrons are in one atom of W 3+ ? 3 protons 4 neutrons 2 electrons 74 protons 110 neutrons 71 electrons

44 Make up your own problem for each format used. Then give it to your neighbor or Ms. Adams to try Make up your own problem for each format used. Then give it to your neighbor or Ms. Adams to try


Download ppt "The Atom Elements! Elements! Elements!. Objectives Atomic Structure The Atomic Theory and History Atomic Math Atomic Structure The Atomic Theory and History."

Similar presentations


Ads by Google