Chemistry 3A Name:

Chapter 4

Problem Set IV

Spring ‘09

Instructor: B. Williams

This is not a graded assignment. Do not turn in.

1)  Use a periodic table to complete the list of elements, symbols, group numbers, and atomic number.

Element
Name / ChemicalSymbol / Group
Number / Atomic number
Boron
/ B / IIIA / 5
Lithium / Li / IA / 3
Magnesium / Mg / IIA / 12
Sulfur / S / VIA / 16

Chlorine

/ Cl / VIIA / 17

Carbon

/ C / IVA / 6

Chromium

/ Cr / VIB / 24

Strontium

/ Sr / IIA / 38

Silver

/ Ag / IB / 47

Bromine

/ Br / VIIA / 35

Barium

/ Ba / IIA / 56

Tin

/ Sn / IVA / 50

Selenium

/ Se / VIA / 34

Gold

/ Au / IB / 79

Zinc

/ Zn / IIB / 30

Beryllium

/ Be / IIA / 4

Argon

/ Ar / VIIIA / 18

Phosphorous

/ P / VA / 15

Aluminum

/ Al / IIIA / 13

Calcium

/ Ca / IIA / 20

Titanium

/ Ti / IVB / 22

Bismuth

/ Bi / VA / 83

Krypton

/ Kr / VIIIA / 36

2)  Complete the following table for each neutral atom.

Element
Name / Nuclear
Symbol / Atomic
No. / Mass
No. / Number of
Protons / Number of Neutrons / Number of Electrons
Nickel
/ / 28 / 58 / 28 / 30 / 28
Calcium / / 20 / 40 / 20 / 20 / 20
Chlorine / / 17 / 35 / 17 / 18 / 17
Barium / / 56 / 137 / 56 / 81 / 56

3)  Two isotopes of copper are naturally occurring: at 69.15% (62.930 amu) and at 30.85% (64.928 amu). Calculate the atomic mass of copper.

4)  Write the symbol and the name for each X and the number of protons and neutrons.

Element
Name / Chemical Symbol / Number of
Protons / Number of Neutrons
/ Neon / Ne / 10 / 10
/ Magnesium / Mg / 12 / 12
/ Silicon / Si / 14 / 14
/ Neon / Ne / 10 / 11
/ Phosphorous / P / 15 / 16

5)  Write the electron arrangement for each of the following atoms. Indicate how many electrons are in the outer energy level of each atom.

a)  sulfur 2e-, 8e-, 6e- 6e-

b)  oxygen 2e-, 6e- 6e-

c)  argon 2e-, 8e-, 8e- 8e-

d)  an atom with Z = 17 2e-, 8e-, 7e- 7e-

6)  State the number of electrons in the outermost energy level (valence electrons), the group number for each element, and the electron-dot symbol for the given elements:

Element Valence Electrons Group number Dot symbol

a)  carbon 4 IVA

b)  aluminum 3 IIIA

c)  silicon 4 IVA

d)  potassium 1 IA

e)  fluorine 7 VIIA

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