How Does the Number of Valence Electrons Vary on Moving from Left Or Right In the Second Period of the Periodic Table? - Science

Advertisements
Advertisements

How does the number of valence electrons vary on moving from left or right in the second period of the periodic table?

Advertisements

Solution

In the second period of the periodic table, the number of valence electrons increases from 1 to 8 on moving from left to right.

  Is there an error in this question or solution?
Chapter 5: Periodic Classification Of Elements - Exercise 2 [Page 303]

APPEARS IN

Lakhmir Singh Class 10 Chemistry (Science)
Chapter 5 Periodic Classification Of Elements
Exercise 2 | Q 12.2 | Page 303

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?

Write the number of horizontal rows in the modern periodic table. What are these rows called?


Consider two elements 'X' (Atomic number 17) and 'Y' (Atomic number 20)

(i) Write the positions of these elements in the modern periodic table giving justification.

(ii) Write the formula of the compound formed by the combination of 'X' and 'Y'.

(iii) Draw the electron-dot structure of the compound formed and state the nature of the bond formed between the two elements ?


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

As, C, Hg, Mg, S, Si


The metal of Group 2 from top to bottom arc Be, Mg, Ca, Sr, and Ba.

1) Which one of these elements will form ions most readily and why?

2) State the common feature in the electronic configuration of all these elements.


Differentiate between Normal elements and Transition elements.


Arrange the following elements in the increasing order of their metallic character:
Mg, Ca, K, Ga


The atomic radii of three elements X, Y and Z of a period of the periodic table are 186 pm; 104 pm and 143 pm respectively. Giving a reason, arrange these elements in the increasing order of atomic numbers in the period.

 


Why do elements in the same group show similar properties but the elements in different groups show different properties?


Which of the following is the valence shell for the elements of second period of the modern periodic table?

(a) M shell
(b) K shell
(c) L shell
(d) N shell


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


State the name assigned to this group?


Why fluorine has higher E.N. than chorine?


How does the number of:
valence electrons and 


A metal M forms as oxide having the formula `M_2O_3`. It belongs to third period. Write the atomic number and valency of the metal.


An element 'X' (Atomic number – 20) burns in the presence of oxygen to form a basic oxide.
(a) Identify the element and write its electronic configuration.
(b) State its group number and period number in the Modern Periodic Table.
(c) Write a balanced chemical equation for the reaction when this oxide is dissolved in water.


Four elements P, Q, R and S belong to the third period of the Modern Periodic Table and have respectively 1, 3, 5 and 7 electrons in their outermost shells. Write the electronic configurations of Q and R and determine their valences. Write the molecular formula of the compound formed when P and S combine.

 


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?

Fill in the blank
There are ______ groups and ______ periods in the modern form of periodic table. 


Choose the most appropriate answer from the following list of oxides which fit the description.
A basic oxide


Choose the most appropriate answer from the following list of oxides which fit the description.
An amphoteric oxide


Arrange the following as per instruction given in the bracket.

Cl, F, Br, I (increasing electron affinity)


Atomic numbers of element A, B, C, D, E, F are 8, 7, 11, 12, 13 and 9 respectively . State the type of ions they form. 


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

Alkaline earth metal in period 3.


State the nature of compounds formed when group 17 elements combine with (i) metals (ii) non-metals.


An element A has 2 electrons in its fourth shell. State:

its valency


An element A has 2 electrons in its fourth shell. State:

position in the periodic table


An element A has 2 electrons in its fourth shell. State:

is it 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.


Based on the group valency of element write the molecular formula of the following compound giving justification:

Compound formed when an element A of group 2 combines with an element B of group seventeen.


Name the elements in Period 1.


Name the period which is the shortest period of the periodic table.


State the property trends in general of elements on moving down in a group of the periodic table.


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

A metalloid in period 2 and in period 3.


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×