1. The first classification of elements is attempted by ...........
2. The modern periodic table has ........... periods.
3. The first period has ......... elements.
4. The ......... period is incomplete.
5. Elements from atomic number 58 to 71 are known as .......
6. In a group the electronegativity .......... from the top to bottom.
7. Addition of hydrogen to a given compound is called ......
8. The chemical formula for magnesite is .....
9. Group II A metals are extracted by ......
10. ........... and ........... are added to MgCl2 during Mg extraction.
Answers: 1) Dobereiner; 2) Seven; 3) Two; 4) Seventh; 5) Lanthanides; 6) Decreases; 7) Reduction; 8) MgCO3; 9) Electrolytic reduction; 10) NaCl2. KCl
Match the following:
Group A Group B
1. First period ( ) A) Inert gases
2. d-block elements ( ) B) Inner transition elements
3. Sand p block elements ( ) C) Two elements
4. Zero Group ( ) D) Representative elements
5. f-block elements ( ) E) Transition elements
Answers: 1-C; 2-E; 3-D; 4-A; 5-B.
Multiple choice questions:
1. Mendeleef's Periodic table is based on the -
A) Atomic weight B) Atomic number C) Atomic radius D) Atomic volume
2. The ionization potential in a group from top to bottom
A) Decreases B) Increases C) Remains the same D) Increases and decreases
3. Which of the following is an ore of Mg?
A) Beryl B) Barytes C) Carnalite D) Hematite
4. Dolomite is a mineral of
A) Mg B) Ca C) Ba D) Al
Answers: 1-A; 2-A; 3 -C; 4-A.
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