For Each of the Following Triads, Name the Element with the Characteristics Specified Below: Elements Least Atomic Radius Chemically Least Reactive (I) F, Cl, Br (Ii) Li, Na, K .................... .................... .................... .................... - Science

Advertisements
Advertisements

For each of the following triads, name the element with the characteristics specified below:

Elements Least atomic radius Chemically least reactive
(i) F, Cl, Br
(ii) Li, Na, K
....................
....................
....................
....................

 

Advertisements

Solution

Elements Least atomic radius Chemically least reactive
(i) F, Cl, Br F   Br
(ii)Li, Na, K Li Li
  Is there an error in this question or solution?
Chapter 5: Periodic Classification Of Elements - Exercise 2 [Page 305]

APPEARS IN

Lakhmir Singh Class 10 Chemistry (Science)
Chapter 5 Periodic Classification Of Elements
Exercise 2 | Q 35.3 | Page 305

Video TutorialsVIEW ALL [2]

RELATED QUESTIONS

Fill in the blank:

The formulae of chloride of metal M is MCl2. The metal M belongs to ……………. group.


Elements in the same group show the same valency. Give scientific reason.


Write the electronic configuration of K and Ne.


The atomic masses of three elements A, B and C having similar chemical properties are 7, 23 and 39, respectively.

  1. Calculate the average atomic mass of elements A and C.
  2. Compare the average atomic mass with atomic mass of B.
  3. What could the elements A, B and C be?

Two elements ‘P’ and ‘Q’ belong to the same period of the modern periodic table and are in Group 1 and Group 2, respectively. Compare their following characteristics in tabular form:-

(a) The number of electrons in their atoms

(b) The sizes of their atoms

(c) Their metallic character

(d) Their tendencies to lose electrons

(e) The formula of their oxides

(f) The formula of their chlorides


Two elements ‘A’ and ‘B’ belong to the 3rd period of Modern periodic table and are in group 2 and 13, respectively. Compare their following characteristics in tabular form:-

(a) Number of electrons in their atoms

(b) Size of their atoms

(c) Their tendencies to lose electrons

(d) The formula of their oxides

(e) Their metallic character

(f) The formula of their chlorides


Classify the following elements into metals, non-metals and metalliods

As, C, Hg, Mg, S, Si


Calculate the number of gram atoms in 4.6 grams of sodium (Na = 23)


Differentiate between Normal elements and Transition elements.


Rewrite the following statement after correction, if necessary:

Elements in the same period have equal valency


Fill in the blank in the following statement:

On moving form right to left in the second period, the number of valency electrons ...............


 How does Chemical reactivity of elements change on going from left to right in a period of the periodic table?

Give example in support of your answer.


 How does the tendency to lose electrons change as we go down in group 1 of the periodic table? Why does it change this way?


Name two properties of elements whose magnitudes change when going from top to bottom in a group of the periodic table. In what manner do they change?


The element which has the maximum number of valence electrons is:
(a) Na
(b) P
(c) Si
(d) A


Which one of the following does not increase while moving down the group of the periodic table?


Correct the statements.

Elements in the same periods have equal valency.


State the trends in chemical reactivity :

Down the group 


Complete the following sentences. 

The properties of the elements are a periodic function of their …………… (atomic number, mass number, reative atomic mass).


name the elements in period 1.


What will be the valency of an element of atomic number 9 (nine)?


Calculate the valency of element X whose atomic number is 9.


Atomic number of metal ‚A‛ is 11, while atomic number of metal ‚B‛ is 20. Which of them will be more reactive? Write the chemical reaction of dilute HCl  with metal ‚A‛.


Taking into consideration the period of the elements given below, answer the following questions: 

Elements Atomic Radius (pm)
O 66
B 88
C 77
N 74
Be 111
Li 152
  1. Arrange the above elements in decreasing order of their atomic radii.
  2. State the period to which the above elements belong.
  3. Why this arrangement of elements is similar to the above period of modern periodic table?
  4. Which of the above elements have the biggest and the smallest atom?
  5. What is the periodic trend observed in the variation of atomic radius while going from left to right within a period?

What is modern periodic law?


Explain, the statement 'In each period, the atomic radii gradually decrease with increase in atomic number'. Give one example to justify your answer.


State the number of elements in period 1, period 2 and period 3 of the periodic table.


The following questions refer to the Periodic Table.
Name the first and last element in period 2.


Choose the correct answer from the choice given:
An element A belonging to Period 3 and Group II will have


An element belongs to the third period and Group IIIA (13) of the periodic table. State: if it is a metal or non-metal?


(a) Fill in the blanks and rewrite the completed statements: 

(i) ________ group in the periodic table contains elements that are all gases at room temperature. 

(ii) Very fine particles mainly scatter ______ light.


Fill in the blank and rewrite the completed statement:

________ group in the periodic table contains elements that are all gases at room temperature.


Give Scientific Reason:
Atomic size increase down the group.

Answer the following question:
State the four blocks of the modern periodic table based on the electronic configuration of elements.


Supply the missing word from those in bracket:

If an element has one electron in its outermost energy level [shell] then it is likely to be _______.


Name or state following with reference to the element of the first three periods of the periodic table.

The valency of elements in group 1 [I–A].


Name or state following with reference to the element of the first three periods of the periodic table.

A non-metal in period 2 having electronic configuration 2, 6.


Name or state following with reference to the element of the first three periods of the periodic table.

A covalent compound formed between an element in period 1 and a halogen.


Name or state following with reference to the element of the first three periods of the periodic table.

A metal in period 3 having valency 3.


Name or state following with reference to the element of the first three periods of the periodic table.

The formula of the hydroxide of the element having electronic configuration 2, 8, 2.


Name or state following with reference to the element of the first three periods of the periodic table.

The valency of the element in period 3 having atomic number 17.


Select the correct answer from the options given below.

It is a period having elements from atomic no. 11 to 18.


Give a reason for the following:

A transition from metallic to non-metallic elements is seen on moving from left to right in a period of the periodic table.


Share
Notifications



      Forgot password?
Use app×