Alchemy Unit – Investigation III

1. Alchemy Unit – Investigation III Lesson 2: Building Atoms

2. Helium, He Berylium, Be ChemCatalyst • A Bohr model of a helium atom and a beryllium atom are given below. (cont.) Unit 1 • Investigation III

3. (cont.) • List threesimilarities and three differences between Be and He. • How do you think a gold atom is different from a copper atom? Unit 1 • Investigation III

4. The Big Question • What does the periodic table tells us about the structures of different atoms? Unit 1 • Investigation III

5. You will be able to: • Use the periodic table to identify the properties of an element’s atoms. Unit 1 • Investigation III

6. Notes & Definitions • Atomic number is the number of protons in the nucleus of an atom. • Mass number is the mass of an individual atom. Unit 1 • Investigation III

7. Beryllium Atom Fluorine Atom Carbon Atom Activity • Purpose: This lesson will formally introduce you to atomic structure by first looking at Bohr models. (cont.) Unit 1 • Investigation III

8. Answer the following questions: • Label the electrons, nucleus, neutrons and protons in the pictures on the worksheet. • Each atom is electrically neutral. Can you explain why? • How did you know which were the protons and which were the neutrons? • Is the nucleus of these atoms positive, negative or neutral? Explain. Unit 1 • Investigation III

9. 5. Fill in the following table Unit 1 • Investigation III

10. Answer the following questions: • 6. How did you figure out the number of electrons? • 7. How did you figure out the number of protons? • 8. How did you figure out the number of neutrons? • 9. How does the mass number of each atom compare to the atomic weight given on the periodic table? Unit 1 • Investigation III

11. Question 10: Draw a nitrogen atom Unit 1 • Investigation III

12. Making Sense • If you know the atomic number of an element, what other information can you figure out about the atoms of that element? • If you know the atomic number of an element, can you figure out how many neutrons an atom of that element has? Can you come up with a close guess? Explain. Unit 1 • Investigation III

13. Making Sense #3 • Examine Tellurium (Te) and Iodine (I) on the periodic table. What are their atomic numbers? What are their atomic weights? • Why do you think iodine’s atomic weight is less than tellurium’s, even though its atomic number is higher? • Can you find another example like this? Unit 1 • Investigation III

14. Notes & Definitions, revisions and additions • Mass number is the number of protons plus the number of neutrons. • Atomic mass is the “weight” or mass of a single atom. • Atomic weight is the decimal number on the periodic table. Unit 1 • Investigation III

15. Atomic Structure & Alchemy • How are gold and copper atoms different? • To change copper into gold, what would we have to do to a copper atom? • If you were trying to make gold from another substance, is there a better starting material than copper? Unit 1 • Investigation III

16. Check-In • Use your periodic table to identify the following elements: • a) Atomic number 18 • b) Has three electrons • c) Atomic mass of 16.0 Unit 1 • Investigation III

17. Wrap-Up • Each successive element has one more proton than the element preceding it. • The atomic number is equal to the number of protons. (cont.) Unit 1 • Investigation III

18. (cont.) • The number of electrons is equal to the number of protons (as long as the atom is neutral). • The mass number is equal to the number of protons plus the number of neutrons (most of the mass is found in the nucleus). Unit 1 • Investigation III