Recitation workshop Module 3 PDF

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Recitation Group Weekly Course Work...

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Recitation Workshop 3

Module 3

Worth 5 pts

1. Write the symbol of the element described by the following: a. Group 7A (17) and period 5 I b. Group 2A (2) and period 3 Mg c. Group 2B (12) and period 4 Zn d. Group 3A (13) and period 2 B 2. In your own words, why is it useful to know if two elements are in the same group? Elements that are in the same group also have the same amount of electrons in the outermost orbital. Ex. All elements in group 1 have 1 electron in their outermost orbital. 3. Use the periodic table to classify each of the following elements by their group, period, group name (if any), and element type (metal, metalloid or nonmetal). a. Cl (chlorine) Group: 7a (17)

Group name: Halogen

Period: 3

Element type: Nonmetal a. b. Li (lithium)

Group: 1a (1)

Group name: Alkali Metal

Period: 2

Element type: Metal a. c. Ba (barium)

Group: 2a (2)

Group name: Alkaline Earth Metal

Period: 6

Element type: Metal b. d. Kr (krypton)

Group: 8a (18)

Group name: Noble Gasses

Period: 4

Element type: Nonmetal c.

4. Classify the following elements as metals, metalloids or nonmetals.

Recitation Workshop 3

Module 3

Worth 5 pts

a. Na Metal b. Zn Metal c. F Nonmetal d. W Metal e. Si Metalloid f. Rn Nonmetal g. As Metalloid h. H Nonmetal 5. For each statement, determine the subatomic particle(s) being described. a. Found in the mostly empty volume of the atom Electron b. Has a positive charge Proton c. Found at the nucleus of the atom Proton and Neutron d. Included in the mass of the atom Protons and Neutrons e. Has no charge Neutron 6. Write the symbol for the following: a. A neutral atom with 42 protons and 48 neutrons: Mo b. A neutral atom with 15 protons and 16 neutrons: P c. A neutral atom with 53 protons and 61 neutrons: I 7. Complete the table below

At o m ic N u m b er

Is ot o p e

N u m b er of Pr ot o n s

M a s s N u m b er

N u m be r of N eu tr on s

40

C a

20

40

20

20

Recitation Workshop 3

Module 3

2 6

Fe

Cd

5 6

8

Sr

38

26

1 0 5

48

O

Worth 5 pts

16 7 1

30

4 8

64

48

8

38

38

1. 8. Evaluate each statement about isotopes as either true or false: a. Isotopes have different numbers of protons: _____false__________ b. Isotopes have different numbers of neutrons: ____true___________ c. Isotopes have different masses: ____true___________ d. Isotopes have different chemical properties: _____false__________ e. Isotopes are different atomic numbers: _____false__________ 8. A sample of chlorine has two naturally occurring isotopes. The isotope35Cl (mass=35.28 amu), makes up 72.5% of the sample, and the isotope37Cl (mass=37.30 amu), makes up the rest. What is the average atomic mass of the sample of chlorine? 35.84 is the average atomic mass of chlorine 9. If you have an electron in then= 3 energy level, what are the possible sublevels it can have? 3 10. What is the maximum number of electrons that can be in then= 2 energy level in an atom? 8 11. Indicate the principle quantum number and sublevel that the highest-energy electron would have in the following atoms (e.g. Ar: 3p): a. Mg: 3s b. Se: 4p c. Cr: 3d d. La: 4f e. N: 2p f. K: 4s

Recitation Workshop 3

Module 3

Worth 5 pts

12. Write the electron configurations for the following atoms. You can use either the regular or abbreviated notation: a. Al: 1s2 2s2 2p5 3s2 3p1 b. Ge: [Ar] 4s2 3d10 4p2 c. Ti: [Xe] 6s2 4f14 5d10 6p1 d. Cr: [Ar] 4s1 3d5 13. Watch the following video and describe in your own words why the electron configurations for Cr and Cu are special? https://www.youtube.com/watch?v=sLgI7jRf4rM The electron configuration for Cr and Cu are special because one of the s electrons jumps into the 3d sublevel which adds another electron to the level. For Cr, instead of being 4s2 2d4 it is actually 4s1 3d5 and for Cu instead of being 4s2 3d 9 the correct way is 4s1 3d10....