Chemistry Unit 4 Study Guide

1. ChemistryUnit 4 Study Guide You may use this study guide to review for your test; practice your new skills or review old concepts. Each topic has several questions relating to it, this should help with giving you plenty of practice.

3. Scientists A Question A Who is considered to be the father of the modern atomic theory? John Dalton

4. Scientists A Question B Who is considered to be the “father of the periodic table” Dmitri Mendeleev

5. Scientists A Question C What was Marie Curie responsible for discovering? Radioactivity, discovered 2 new elements and discovered x rays.

6. Scientists B Question A What was Rutherford’s most notable discovery? Discovered the nucleus of the atom in his gold foil experiment.

7. Scientists B Question B Who discovered the proton? Rutherford

8. Scientists B Question C Who discovered the electron? J.J. Thomson

9. Scientists C Question A List in order the major scientists in the world of atomic chemistry from earliest to most recent. Make sure that you know their biggest accomplishments. Democritus- first mention of atom Dalton- Atomic theory Thomson- electron Curie- xrays, radiation Rutherford- proton and nucleus Bohr- electron orbits Schrodinger- quantum model Chadwick- neutron

10. Scientists C Question B What do Bohr’s orbitals tell us about the atom’s electrons? It tells us the path the electrons are following with about 90% certainty

11. Scientists C Question C Schrodinger did not develop the wave model himself, he used Bohr’s work as a starting point to explain de Broglie’s matter waves. What did Schrodinger contribute to the quantum theory? The mathematical equations that explained and supported the quantum theory.

12. Electron Configuration Theory A Electrons in electron shells always fill from ______energy to _______energy. Lowest, highest

13. Electron Configuration Theory B How many electrons can each orbital hold? S can hold 2 P can hold 6 D can hold 10 F can hold 14

14. Electron Configuration Theory C What is the maximum number of electrons on each energy level? 1st level- 2 2nd level – 8 3rd level – 18 4th level- 32 5th level -32 6th level- 18

15. Radioactivity A What does an alpha particle consist of? 2 protons and 2 neutrons, in other words a He nucleus.

16. Radioactivity B What does a beta particle consist of? An electron

17. Radioactivity C List in order from highest energy to lowest the three common types of radiation. Gamma, Beta, Alpha

18. Ionization Energy A What does ionization energy tell us? The amount of energy required to remove an electron from an element’s outside shell. The higher the ionization energy the more difficult it is to remove the electron.

19. Ionization Energy B If an element has ionization energies of E1 = 235, E2 = 980, E3= 1120; how many valence electrons does this element contain? 1 valence electron, there is a sharp increase in the ionization between E1 and E2 which shows that we have moved from the unfilled electron shell to a filled one.

20. Ionization Energy C What happens to ionization energy as you move across a period on the periodic table? Why do we see this change in ionization energy? Ionization energy increases across the period, this is because the attractive force of the nucleus increases and because the radius of the atom decreases slightly.

21. Reactivity A On the metals side of the periodic table, what happens to the reactivity as you move down the group? Why? As you move down the group the reactivity in metals increases because the valence (reacting) electrons are held more loosely.

22. Reactivity B As you move down the table on the nonmetals side, what happens to the reactivity of the elements and why? As you move down the group on the nonmetal side the reactivity decreases because nonmetals which to attract electrons and the valence electrons are moving farther from the nucleus.

23. Reactivity C From the following pairs of element select the element that will be more reactive. Na and Li Sr and Ra F and Br Na, Ra, F

24. Energy Levels A Which energy level(s) contain a s and a p orbital only? 2nd energy level

25. Energy Levels B At what energy level do we see a d orbital appear? 3rd energy level

26. Energy Levels C Which energy level requires the most energy to remove an electron from? The innermost shell

27. Quantum Theory A In quantum theory it is said that each energy level has more and more energy associated with it. Which two energy levels have the largest difference in energy state? 1st-2nd; 2nd to 3rd; 5th-6th 1st to 2nd, as you move away from the nucleus each energy level has less and less energy difference.

28. Quantum Theory B When is energy released from the movement of electrons? When the are moving up an energy level, when they are moving down an energy level, or when they are moving through their energy level When they are moving down and energy level energy is released. Energy is absorbed when they move up a level.

29. Quantum Theory C Why are the elements that have their valence electrons filling the 3d orbital (the transition metals) present in the 4th row of the periodic table? The d orbital is in between the 3rd and 4th energy level in regards to it’s energy. Therefore it nestles in between the two and is halfway between them. We represent this by having them on the 4th period on the periodic table.

30. Writing Electron Configuration A What is the electron configuration for the element S? 1s22s22p63s23p4

31. Writing Electron Configuration B What is the electron configuration of the valence electrons for the element Ge? 4s24p2

32. Writing Electron Configuration C What element is represented by the configuration 1s22s22p5? F- Flourine

33. Radiation Equations A Please predict the missing part of the following reaction: 22688 Ra → ______ + 22286Rn 42 He

34. Radiation Equations B Please fill in the missing product in the following reaction: 24194Pu→ 0 -1 e + _________ 24195 Am

35. Radiation Equations C What type of radiation is illustrated by the product 0 -1 e? Beta radiation

36. Bonding A What does the Law of Definite Proportions state? That elements will combine in small whole number ratios to produce new compounds.

37. Bonding B What charge will an ion have that was from an atom in group IIA? +2

38. Bonding C What is the relationship between the group number, the number of valence electrons and the ionic charge they will form? The group number indicates the number of valence electrons an atom has. The valence electrons determine what charge the ion will have, very few valence electrons will form + ions and larger numbers of valence electrons form – ions.