The Atom and the Periodic Table

1. The Atom and the Periodic Table Georgia Performance Standards: SPS1. Students will investigate our current understanding of the atom. a. Examine the structure of the atom in terms of proton, electron, and neutron locations. atomic mass and atomic number. atoms with different numbers of neutrons (isotopes). b. Explain the relationship of the proton number to the element’s identity

2. Chemical Symbol-- ______________________________________________ Represents a(n) _______________________ When alone… Capital Letter Examples ________________________ When more than one letter…. Capital letter followed by a lower case letter Examples _____________________________ Chemical Formula -- ____________________________________________ Represents a(n) _________________________ Examples __________________________________________________ Chemical Equation-- ____________________________________________ Represents a(n) _______________________________ Examples_________________________________________________ _________________________________________________

3. Structure of an Atom Atom--________________________________________ Subatomic Particles: 1. ___________________ -- positive charge, found in the nucleus 2. Neutrons – no charge, found in the nucleus 3. ___________________-- negative charge, found in the electron _______________ in energy levels. Nucleus – the ____________-charged dense central portion of the atom. Protons and Neutrons are made up of _______________. Atoms are very very very small… thickness of aluminum foil (around 24,400 atoms stacked)

4. Atomic Model 1. 400 BC, ____________________________ said atoms make up all substances. Atom comes from the latin word “atomos” , meaning __________. Question: Is the meaning of “atom” true? Explain. 2. Atom changed over time. Different scientists discovered the protons, electrons, nucleus, neutrons. Each made models and improved upon the makeup of the atom. 3. The Bohr Model: • Today, we use the _______________ model.

5. Atomic Number The atomic number is equal to the number of _______________________ in an element. • It determines the type of element. ALL Carbon atoms have 6 protons. They may have different numbers of electrons and neutrons, but ALL CARBON ATOMS HAVE 6 PROTONS. Tell the number of protons in the following: Magnesium ___ Potassium ___ Copper ___ Mercury _____

6. Mass in an Atom The __________ of the atom contains most of the mass. Protons are approximately ________ times more mass than electrons. 1 AMU (__________ _________ _____________) =the mass of 1 proton OR 1 neutron Question: Which has more mass? An electron or a proton? ______________________ Question: Which has more mass? A proton or a neutron? _______________________

7. Mass Number Mass Number = the number of _________________ PLUS the number of _______________ of one atom (one isotope) • Protons + Neutrons If you know the Atomic Number and the Mass Number, you can get the number of neutrons in an atom Get Mass Number from name of isotope. Examples: Magnesium-25, Carbon-13 Potassium-36

8. Mass Number Example Mass Number  (Protons + Neutrons) Carbon- 14 M# = 14 Subtract subtract - Atomic Number  (Protons) A# = 6 ________________ ___ Neutrons Number neutrons 8 Find the number of neutrons in the following: (Show work.) Calcium-42 Nitrogen-12 Sulfur-30 Copper-56

9. Isotopes Isotope– atoms of the same element that have DIFFERENT amounts of _________________________. Isotope name written as Carbon-12, Carbon-13 and Carbon-14. How many neutrons are in C-12 _______ C-13 ________ C-14 _______? How many protons are in C-12 _______ C-13 ________ C-14 ________? How many electrons are in C-12 _______ C-13 ________ C-14 _______? What makes C-12 different from C-13 and C-14? The number of _______________ How are they similar? _____________________________________

10. Atomic Mass (Average Atomic Mass) Atomic Mass is NOT THE SAME AS MASS NUMBER. (Sometimes they are used interchangeably but that is incorrect). Atomic Mass – a weighted AVERAGE mass of the different known isotopes Since most elements have more than one isotope, the atomic mass is not always a whole number. Example: Carbon is 12.011 because Carbon has 3 isotopes (C-12, C-13 and C-14). The Atomic Mass is usually closest to the number of the MOST COMMONLY FOUND ISOTOPE. (such as Carbon 12)

11. Calculating Atomic Mass: Assume that C-12 is found 76% of the time, C-13 is 19%, and C-14 is found 5% of the time. C-12 12 X .76 = _____ C-13 13 X .19 = _____ C-14 14 X .05 = _____ _____ Total is the Atomic Mass. Unit: amu Calculate the Atomic Mass of the following elements. Show your work. 1. Assume that Ca-39 is found 16% of the time, Ca-40 is 82%, and Ca-41 is found 2% of the time. 2. Assume that Zn-62 is found 79% of the time, Zn-60 is 12%, and Zn-59 is found 9% of the time.

12. Periodic Table Periodic means “repeating pattern” 1. In the 1860s, ____________________ produced the 1st periodic table. Arranged his periodic table by increasing atomic __________________. Properties in lighter elements could be seen in heavier elements but with increasing reactivity. Mendeleev left blanks in his periodic table to align similar chemical properties. He predicted the properties and atomic masses of undiscovered elements He was right. 2. In 1913, ___________________________________ rearranged the periodic table by the atomic _______________. The inconsistencies disappeared. TODAY’S PERIODIC TABLE is arranged according to increasing atomic number.

13. Periodic Table Arrangement Groups or ________________________ are VERTICAL columns. The elements have similar properties. Elements in Group 2 are ____________, ____________ and __________ Rows or ____________________ are the HORIZONTAL rows. • They have the same number of energy levels. Elements in Row 2 are _________, ___________ and _____________ Valence Electrons Valence Electron– electrons in the ___________________________. • Can use electron dot diagram (Lewis structure) to show the valence electrons The pattern of valence electrons across the periodic table (from left to right) 1,2,3,4,5,6,7,8

14. Electron Dot Diagram (Lewis Structure) • Dots represent the __________________. • The _________________ represents the nucleus and all the inner energy level electrons.

15. Electron dots are simplified versions of the atom focusing on valence electrons Each group has same number of valence electrons so they have similar properties Draw the Lewis structures for the following elements: argon, boron, calcium, aluminum and helium

16. Classifying the Periodic TableIn the following table, tell where metals, metalloids and nonmetals are found on the periodic table, list 4 (general) characteristics of each and give 4 examples of each.