Taking into Consideration the Period of the Elements Given Below, Answer the Following Questions : (Pm) - Science and Technology 1

Advertisements
Advertisements
Answer in Brief

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?
Advertisements

Solution

  1. Li > Be > B > C > N > O
  2. 2nd period
  3. Yes, this elemental arrangement resembles the era of the contemporary periodic table mentioned above. The positive charge on the nucleus grows one unit at a time as we move from left to right over a period of time, but when electrons are added to the same orbit, the pull away from the nucleus increases, reducing the size of the atom.
  4. Li is the biggest atom oxygen is the smallest atom
  5. While going from left to right within a period atomic radius decreases due to an increase in effective nuclear charge.
  Is there an error in this question or solution?
2018-2019 (March) Set 1

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?

From the following elements :

4Be; 9F; 19K; 20Ca

(i) Select the element having one electron is the outermost shell.

(ii) two elements of the same group.

Write the formula of and mention the nature of the compound formed by the union of 19K and element X(2, 8, 7).


Define the term : Valency


Which element has a total of two shells, with three electrons in its valence shell?


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

As, C, Hg, Mg, S, Si


Differentiate between Normal elements and Transition elements.


Arrange the following elements in increasing order of their atomic radii:
Li, Be, F, N


Rewrite the following statement after correction, if necessary:

The metallic character of elements in a period increases gradually on moving from left to right.


An element X belongs to group 2 and another element Y belongs to group 15 of the periodic table:

(a) What is the number of valence electron in X?
(b) What is the valency of X?
(c) What is the number of valence electrons in Y?
(d) What is the valency of Y?
Explain how you have arrived at your answers.


 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.


 In terms of electronic configurations, explain the variation in the size of the atoms of the elements belonging to the same period and same group ?


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


The atomic numbers of three elements A, B and C are given below:

Element Atomic number
A 5
B 7
C 10


(i) Which element belongs to group 18?
(ii) Which element belongs to group 15?
(iii) Which element belongs to group 13?
(iv) To which period/periods do these elements belong?


An element A has atomic number 14. To which period does this element belong and how many elements are there in this period.


An element X belong to 4th period and 17th group, state.

name the family to which it belong.


How does the number of:
valence electrons and 


Complete the following sentences. 

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


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‛.


State whether the following statement is true or false
Similar electronic configuration is repeated after intervals of 2, 8, 8, 18 and 32.


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


Select the correct answer
Identify the metalloid


Copy and complete the following sentence choosing the correct word or words from those given below, at the end of the sentence:
The similarities in the properties of elements belonging to a group are because they have the same ______ 


Choose the correct answer from the choice given:
In the periodic table, alkali metals are placed in the group __________


Parts (a) to (e) refer to change in the properties of elements on moving from left to right across a period of the periodic table. For each property, choose the correct answer. 

The non-metallic character of the elements:


An element belongs to the third period and Group IIIA (13) of the periodic table. State: the number of valence electrons,


Name and state the following with reference to the elements of the first three periods of the periodic table.

Metalloid in Period 3.


Name and state the following with reference to the elements of the first three periods of the periodic table.

Non-metallic elements present in Period 3 of Groups 15 and 16.


(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.


The position of certain elements in the Modern Periodic Table is shown below:

Using the above table answer the following questions giving reasons in each case :
(i) Which element will form only covalent compounds?
(ii) Which element is a non-metal with valency 2?
(iii) Which element is a metal with valency 2?
(iv) Out of H, C, and F which has the largest atomic size?
(v) To which family does H, C, and F belong?


Copy and complete the following sentence choosing the correct word or words from those given in bracket at the end the sentence:

The similarities in the properties of a group of elements are because they have the same _________.


Name the elements in the correct order of their increasing atomic numbers present in the first, second, and third short periods of the periodic table.
State which of the elements are –

  1. metallic 
  2. non-metallic 
  3. noble gases

in each of the periods 2 and 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.

A non-metal in period 2 which is tetravalent.


Select the correct answer from the options given below.

Is the group number of the element whose atomic number is 4.


State the following:

The group which contains highly electropositive metals including sodium.


Complete the table pertaining to the following elements given in Column I.

Column I Elements Atomic Number Electronic Configuration Underline the element present in that group
1. Hydrogen 1 ______ Be/Na/Ca
2. Carbon 6 ______, ______ N/P/Si
3. Nitrogen 7 _______, ______ C/P/S
4. Oxygen 8 _______, ______ N/S/Cl
5. Sulphur 16 _____, ______, _______ O/N/F
6. Chlorine 17 _____, ______, ______ I/O/S

Share
Notifications



      Forgot password?
Use app×