Dr. Parul Srivastava Solutions for Chapter: Periodic Classification of Elements, Exercise 5: Formative Assessment

Four elements along a period have atomic number ($11, 13, 16$ and $17$). The most metallic among these have an atomic number of

Six elements $\mathrm{A}, \mathrm{B}, \mathrm{C}, \mathrm{D}, \mathrm{E}$ and $\mathrm{F}$ have the following atomic numbers ($\mathrm{A} = 12, \mathrm{B} = 17, \mathrm{C} = 18, \mathrm{D} = 7, \mathrm{E} = 9$ and $\mathrm{F} = 11$). Among these elements, the element, which belongs to the $3\mathrm{rd}$ period and has the highest ionisation potential, is

A factor that affects the ionisation potential of an element is

The element, which has the highest electron affinity in the $3\mathrm{rd}$ period is

The element, which has zero electron affinity in the $3\mathrm{rd}$ period is

The statement that is not true about electron affinity is

Down a group, the electron affinity

SOLVE THE PUZZLE
CLUES: Down:
1. I have 26 protons.
3. I am not really an alkali metal, but since I have only 1 electron I behave like them. 
4. I am a metal with 28 electrons.
7. I am a member of the boron family and am the most abundant metal in the Earth's crust.
8. I am a gas with 8 protons and 8 neutrons.
10. I am a member of the carbon family often mistaken for the end of your pencil.

12. I am a metal that is liquid at room temperature.
14. My atomic number is 47 and I am used to make photographic film. 
15. I have 20 neutrons and am found in your teeth and bones. 
16. I am a member of the nitrogen family with 16 neutrons.
18. I am a gas with a mass number of 19.
19. I am the first element in the fourth period used in making fertilizer. 22. You can find me in the carbon family in the fifth period.

22. You can find me in the carbon family in the fifth period.

Across:
2. My atomic mass is $35.453 \mathrm{u}$.
5. I have 2 electrons in the first shell, 8 in the second shell, and 6 in the third shell.
6. I am the head of the carbon family known as the "basis of life".
9. My atomic number is 79.
11. I am a transition metal with 25 electrons.
13. I make up 78% of the air and am found in the 15th group.
14. I am a silvery white metal used to make salt.
17. I am a member of the alkaline earth metals used to make fireworks and medicines.
20. I am a noble gas with 2 electrons.
21. I am the second most abundant element in the Earth's crust and have 14 neutrons.
23. I am a member of the halide family with an atomic number of 53.
24. I am a transition metal with 30 electrons useful in making paint.
25. I am the only element in the halide family that is a liquid.