Question

6.2 - classifying the elements (p. 167 - 173)

1. what chemical properties do the noble - gases share and how does this relate to their electron configuration?
2. for each element tell which period and group the element is in, identify the element, and state whether it is a metal, nonmetal, or metalloid

element period group identity metal, nonmetal, metalloid?
#34
#40
#14
#56
#18
#4
#82
#37

1. classify the following as metals, nonmetals or metalloids:

a) manganese:____
b) arsenic:____
c) carbon:____
d) nitrogen:____
e) niobium:____
f) radium:____

1. iodine is used in many commercial chemicals and dyes. to what family does it belong? what are the other members of this family? how many electrons are in the outermost energy level (valence electrons)?

6.3 - periodic trends (p. 174 - 183)

1. explain why as you go down the periodic table, within a group, atomic radius increases.
2. explain why cl (#17) is smaller then s (#16) considering it has one more proton than sulfur.
3. arrange these elements in order of decreasing atomic size:

a) s, cl, al, na, si, mg, ar, p:____
b) sb, sr, te, i, in, xe, rb:____
c) se, po, o, s, te:____
d) cs, na, li, h, fr, rb, k:____

Explanation:

Step1: Answer question 9

Noble - gases are unreactive due to having a full outer - electron shell (8 electrons, except He which has 2). Their electron configuration is stable. For example, helium has 1s², neon has 1s²2s²2p⁶. This full outer shell makes them very stable and less likely to form chemical bonds.

Step2: Answer question 10

Element #34 is Selenium (Se). It is in period 4, group 16, and is a non - metal.
Element #40 is Zirconium (Zr). It is in period 5, group 4, and is a metal.
Element #14 is Silicon (Si). It is in period 3, group 14, and is a metalloid.
Element #56 is Barium (Ba). It is in period 6, group 2, and is a metal.
Element #18 is Argon (Ar). It is in period 3, group 18, and is a non - metal.
Element #4 is Beryllium (Be). It is in period 2, group 2, and is a metal.
Element #82 is Lead (Pb). It is in period 6, group 14, and is a metal.
Element #37 is Rubidium (Rb). It is in period 5, group 1, and is a metal.

Step3: Answer question 11

A) Manganese is a metal.
B) Arsenic is a metalloid.
C) Carbon is a non - metal.
D) Nitrogen is a non - metal.
E) Niobium is a metal.
F) Radium is a metal.

Step4: Answer question 12

Iodine belongs to the halogen family. Other members are fluorine (F), chlorine (Cl), bromine (Br), and astatine (At). Halogens have 7 valence electrons.

Step5: Answer question 13

As you go down a group in the periodic table, the atomic radius increases because new energy levels (shells) are added. Each new shell is farther from the nucleus, increasing the distance between the outermost electrons and the nucleus.

Step6: Answer question 14

Chlorine is smaller than sulfur despite having one more proton because the extra proton in chlorine increases the effective nuclear charge. This stronger pull on the electrons in the same energy level (3rd energy level for both) causes the electrons to be pulled in closer to the nucleus.

Step7: Answer question 15

A) Na > Mg > Al > Si > P > S > Cl > Ar
B) Rb > Sr > In > Sb > Te > I > Xe
C) Po > Te > Se > S > O
D) Cs > Rb > K > Na > Li > H > Fr (Note: Fr is radioactive and extremely rare, but based on periodic trends)

Answer:

1. Noble gases are unreactive due to full outer - electron shells. Their electron configurations are stable (e.g., He: 1s², Ne: 1s²2s²2p⁶).
2. #34: Period 4, Group 16, Selenium, Non - metal; #40: Period 5, Group 4, Zirconium, Metal; #14: Period 3, Group 14, Silicon, Metalloid; #56: Period 6, Group 2, Barium, Metal; #18: Period 3, Group 18, Argon, Non - metal; #4: Period 2, Group 2, Beryllium, Metal; #82: Period 6, Group 14, Lead, Metal; #37: Period 5, Group 1, Rubidium, Metal
3. A) Metal; B) Metalloid; C) Non - metal; D) Non - metal; E) Metal; F) Metal
4. Halogen family. Other members: F, Cl, Br, At. 7 valence electrons.
5. New energy levels are added as you go down a group, increasing the distance between outermost electrons and the nucleus.
6. The extra proton in Cl increases the effective nuclear charge, pulling electrons closer to the nucleus.
7. A) Na > Mg > Al > Si > P > S > Cl > Ar; B) Rb > Sr > In > Sb > Te > I > Xe; C) Po > Te > Se > S > O; D) Cs > Rb > K > Na > Li > H > Fr