6. Complete the following table using the periodic table. (AS1)
| Period
number |
Filling up orbital’s
(sub shells)
|
Maximum number of
electrons, filled in all
the sub shells
|
Total no. of
elements in the
period |
| 1. |
|
|
|
| 2. |
|
|
|
| 3. |
|
|
|
| 4. |
4s, 3d, 4p |
18 |
18 |
| 5. |
|
|
|
| 6. |
|
|
|
| 7. |
7s, 5f, 6d, 7p |
32 |
incomplete |
7. Complete the following table using the periodic table. (AS1
)
8. Why was the basis of classification of elements changed from the atomic mass to the atomic
number? (AS1
)
9. What is a periodic property? How do the following properties change in a group and period?
Explain. (AS1
)
i) (a) Atomic radius (b) Ionization energy (c) Electron affinity (d) Electronegativity.
ii) Explain the ionization energy order in the following sets of elements:
a) Na, Al, Cl b) Li, Be, B c) C, N, O d) F, Ne, Na e) Be, Mg, Ca. (AS1
)
Application of concepts
1. Given below is the electronic configuration of elements A, B, C, D. (AS1
)
A.1s2
2s2 1. Which are the elements coming within the same period
B.1s2 2s2 2p6 3s2 2. Which are the ones coming within the same group?
C.1s2 2s2 2p6 3s2 3p3 3. Which are the noble gas elements?
D.1s2 2s2 2p6 4. To which group and period does the element ‘C ‘belong
page no:146
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