Tag: group 17 elements

Questions Related to group 17 elements

The elements with atomic numbers 9, 17, 35, 53 and 85 belong to noble gases columnz__________.

  1. True

  2. False


Correct Option: B
Explanation:

The atomic number of elements are 9,17,35,53,85.
Electronic configuration of elements will be
9  = 2,7
17= 2,8,7
35= 2,8,18,7
53=2,8,18,18,7
85=2,8,18,18,32,7
The pattern shows that all elements have 7 electron in their outermost valence shell and all these elements belong to halogens.

Elements of which group form anions most readily:

  1. oxygen family

  2. nitrogen group

  3. halogen family

  4. carbon group


Correct Option: C
Explanation:

Halogens need to lose only one electron to form an anion, and thus, their tendency to form an anion is highest. 

In the third excited state the number of unpaired electrons in chlorine atom is:

  1. 5

  2. 7

  3. 3

  4. 1


Correct Option: B
Explanation:

The general electronic configuration of chlorine is $[Ne] 3s^{2} 3p^{5}$

When electrons are excited in chlorine, the electrons enter into 3d subshell then electronic configuration of chlorine is given as:
$[Ne] 3s^{1} 3p^{3} 3d^{3}$
Thus the number of unpaired electrons will be 7.

Which of the following shows only one oxidation state in its compounds:

  1. F

  2. Cl

  3. Br

  4. I


Correct Option: A
Explanation:

F does not have empty d-orbitals o it show only one oxidation state. In othens electrons can excite to empty d-orbitals and show variable oxidation state

The number of p-electrons in bromine atom is:

  1. 17

  2. 7

  3. 15

  4. 13


Correct Option: A
Explanation:

$Br - 35$

Its electronic configuration is given as:
$1s^22s^22p^63s^23p^64s^23d^{10}4p^5$
So, total p-electrons =6+6+5
= 17

Which one of the following is the correct order for the bond energies of halogen molecules?

  1. $Cl _2>Br _2>I _2$

  2. $Br _2>Cl _2>l _2$

  3. $l _2>Cl _2>Br _2$

  4. $I _2>Br _2>Cl _2$


Correct Option: A
Explanation:

Bond energy is inversely proportional to molecular mass as van der wall forces exist  between molecules of halogens
$\therefore$ Bond Energy order:
$Cl _2>Br _2>I _2$

The electro valency theory explains that atoms are held together by an attractive force.

  1. True

  2. False


Correct Option: A
Explanation:

Electrovalency theory (valence band theory) explains two atoms that have an unpaired electron in their orbitals can overlap to give rise to chemical bond and chemical bond nothing but an attractive force between two atoms.

Arrange the following atoms in the order of increasing atomic radius.
F, Cl, C, O

  1. F, Cl, O, C

  2. C, O, F,Cl

  3. O, C, F, Cl

  4. F, O, C, Cl


Correct Option: D
Explanation:

As we move along a period from left to right, number of proton increases and valence shell remains same, so, radius of atom decreases.
Also, as we move down the group, number of valence shell increases, so, size of atom increases so order of radii is
 F < O < C < CI.

Sea weeds are an important source of :

  1. Iron

  2. Chlorine

  3. Iodine

  4. Bromine


Correct Option: C
Explanation:

Iodine is a component of almost every living plant and animal. No standard measurements of iodine in food exist because iodine concentrations vary across the world. In general, foods from the sea contain the most iodine, followed by animal foods, then plant foods. Of all foods, seaweed (like kelp), is the most well known and reliable source of natural iodine. Egg and dairy products can also be good sources.

Which is the most active element among folllowing?

  1. Chlorine

  2. Oxygen

  3. Sulfur

  4. Fluorine


Correct Option: D
Explanation:

Most active element is Fluorine. The reduction potential of fluorine is very high. Hence, it is extremely reactive in nature. Also F-F bond energy is low (38 kcal/mol). The valence shell electron configuration of fluorine $2s^22p^5$  indicates that it has very strong tendency to take up one electron to attain stable noble gas configuration. Hence, it has high reactivity.