Tag: chemistry

Questions Related to chemistry

The outer most electronic configuration of the most electronegative element is:

chemistry p- block elements-ii group 17 elements - general properties group 17 elements group 17 elements - properties

  1. $\mathrm{n}\mathrm{s}^{2}\mathrm{n}\mathrm{p}^{3}$

  2. $\mathrm{n}\mathrm{s}^{2}\mathrm{n}\mathrm{p}^{4}$

  3. $\mathrm{n}\mathrm{s}^{2}\mathrm{n}\mathrm{p}^{5}$

  4. $\mathrm{n}\mathrm{s}^{2}\mathrm{n}\mathrm{p}^{6}$

Show answer
Correct Option: C
Explanation:

Halogens are most electronegative.


Therefore outer electronic configuration is $ns^{2}\ np^{5}$

Option C is correct.

Generally non-metals are non-lustrous. Exception to this property is-

chemistry p- block elements-ii group 17 elements - general properties group 17 elements group 17 elements - properties

  1. Flourine

  2. Chlorine

  3. Bromine

  4. Iodine

Show answer
Correct Option: D
Explanation:

Lime water is calcium hydroxide and is a base so it turns phenolphthalein solution (an indicator) pink.

The halogen $($Group $17$ elements$)$:

chemistry p- block elements-ii group 17 elements - general properties group 17 elements group 17 elements - properties

  1. have an electron configuration of a noble gas less seven electrons

  2. are highly electro positive

  3. show variable oxidation state of $-1, +1, +3, +5$ and $+7$ in their various compounds

  4. forms a volatile, covalent hydrides $HX$ in which the halogen $(X)$ shows an oxidation state of $+1$

Show answer
Correct Option: C
Explanation:

Fluorine is the most electronegative in halogen family so it has oxidation number of -1 in all its compounds but Cl,Br and I are less electronegative so these elements prepare compounds with oxidation number of +1,+3,+5 and +7.

Which of the following have large electronegativity values?

chemistry p- block elements-ii group 17 elements - general properties group 17 elements group 17 elements - properties

  1. Alkali metals

  2. Alkaline Earth metals

  3. Metalloids

  4. Halogens

  5. Rare earth metals

Show answer
Correct Option: D
Explanation:

Electronegativity is a chemical property that describes the tendency of the atom to attract electrons towards itself.

Halogens have 7 electrons in their valence shell.
They need only 1 electron to complete their octet.
Hence, halogens are highly electronegative.

Assertion: Fluorine has the highest value for electronegativity.
Reason: Fluorine has the greatest attraction for electrons.

chemistry p- block elements-ii group 17 elements - general properties group 17 elements group 17 elements - properties

  1. Both Assertion and Reason are true and Reason is the correct explanation of Assertion

  2. Both Assertion and Reason are true but the Reason is not the correct explanation of Assertion

  3. The Assertion is true but Reason is false

  4. The Assertion is false but the reason is true

  5. Both Assertion and Reason are false

Show answer
Correct Option: A
Explanation:

Both Assertion and Reason are true and the Reason is the correct explanation of the Assertion. 


Fluorine has the highest electronegativity. This is because its electrons are held very strongly by the nucleus as it has a small atomic radius and high nuclear charge density.

Hence, the correct option is A.

Among the following which has higher electron affinity value ?

chemistry p- block elements-ii group 17 elements - general properties group 17 elements group 17 elements - properties

  1. Fluorine

  2. Chlorine

  3. Bromine

  4. Iodine

Show answer
Correct Option: B
Explanation:

Electron Affinity: decreases down the group. Since the atomic size increases down the group, electron affinity generally decreases$ ( I < Br < F < Cl)$. An electron will not be as attracted to the nucleus, resulting in a low electron affinity. However, fluorine has a lower electron affinity than chlorine.

With which of the following halogen,germanium does not form a dihalide?

chemistry p- block elements-ii group 17 elements - general properties group 17 elements group 17 elements - properties

  1. Fluorine

  2. Chlorine

  3. Bromine

  4. Iodine

Show answer
Correct Option: C
Explanation:

Germanium forms tetrahalides with all halogens except astatine and forms dihalides with all halogens except bromine and astatine.

Which of the following chalcogen does not make bonds with germanium?

chemistry p- block elements-ii group 17 elements - general properties group 17 elements group 17 elements - properties

  1. Sulfur

  2. Selenium

  3. Tellurium

  4. Polonium

Show answer
Correct Option: D
Explanation:

Chalcogens are chemical elements in group 16 of the periodic table. Germanium bonds to all natural single chalcogens except polonium.

Which of the following element has metallic lustre?

chemistry p- block elements-ii group 17 elements - general properties group 17 elements group 17 elements - properties

  1. $F$

  2. $Cl$

  3. $Br$

  4. $I$

Show answer
Correct Option: D
Explanation:

As we move down the group the metallic character increases which impart lustrousness to the elements.

So the iodine is most lustrous.

Which of the following has most ionisation enthalpy?

chemistry p- block elements-ii group 17 elements - general properties group 17 elements group 17 elements - properties

  1. $F$

  2. $Cl$

  3. $Br$

  4. $I$

Show answer
Correct Option: A
Explanation:

As the atomic size of the Florine is less it has more nuclear charge. So it requires more energy to remove the electron from its outer most orbit. So Florine has high ionization enthalpy and as we move down the group size increases nuclear charge decreases hence Ionization potential.

Hence option A is correect.