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Question
Fill in the blank and rewrite the completed statement:
________ group in the periodic table contains elements that are all gases at room temperature.
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Solution
The 18th group in the periodic table contains elements that are all gases at room temperature.
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RELATED QUESTIONS
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
How many groups and periods are there in the modern periodic table?
Write the number of periods the Modern Periodic Table has. State the changes in valency and metallic character of elements as we move from left to right in a period. Also state the changes, if any, in the valency and atomic size of elements as we move down a group.
What is meant by 'group' in the modern periodic table? How do the following change on moving from top to bottom in a group?
(i) Number of valence electrons
(ii) Number of occupied shells
(iii) Size of atoms
(iv) Metallic character of element
(v) Effective nuclear charge experienced by valence electrons
Based on the group valency of elements state the formula lot the following giving justification for each :-
(i) Oxides of 1st group elements,
(ii) Halides of the elements of group 13, and
(iii) Compounds formed when an element of group 2 combines with, an element of group 16.
How do the valency and the atomic size of the elements vary while going from left to right along a period in the modern periodic table?
Write the number of horizontal rows in the modern periodic table. What are these rows called?
Write any one difference in the electronic configurations of group-1 and group-2 elements ?
Which element has a total of three shells, with four electrons in its valence shell?
Calculate the number of gram atoms in 4.6 grams of sodium (Na = 23)
Calculate the mass of Calcium that will contain the same number of the atom as are present in 3.2 gm of Sulphur.
[Atomic masses: S=32, Ca=40]
How does the valency of elements change of moving from left to right in the third period of the periodic table?
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 Nature of oxides of elements change on going from left to right in a period of the periodic table?
Give examples in support of your answer.
The atomic numbers of the elements Na, Mg, K and Ca are 11, 12, 19 and 20 respectively. The element having the largest atomic radius is:
(a) Mg
(b) Na
(c) K
(d) Ca
Which one of the following does not increase while moving down the group of the periodic table?
In each of the following pair, choose the atom having the bigger size:
(a) Mg (At. No.12) or Cl (At. No.17)
State the trends in physical properties on moving down the group. Give an example to illustrate.
An element X belong to 4th period and 17th group, state.
name the family to which it belong.
Chorine in the periodic table is surrounded by the elements with atomic number 9, 16, 18 and 35.
Which of these have physical and chemical properties resembling chlorine.
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.
In the following table, the positions of six elements A, B, C, D, E and F are given as they are in the Modern Periodic Table :
 |
1 | 2 | 3-12 | 13 | 14 | 15 | 16 | 17 | 18 |
| 2 | A | B | C | D | |||||
| 3 | E | F |
On the basis of the above table, answer the following questions :
(i) Name the element which forms only covalent compounds.
(ii) Name the element which is a metal with valency three.
(iii) Name the element which is a non-metal with valency three.
(iv) Out of B and C, whose atomic radius is bigger and why ?
(v) Write the common name for the family to which the elements D and F belong.
An element 'M' has atomic number 11.
(a) Write its electronic configuration.
(b) State the group to which 'M' belongs.
(c) Is 'M' a metal or a non-metal.
(d) Write the formula of its chloride.
An element 'M' has atomic number 12.
(a) Write its electronic configuration.
(b) State the group to which 'M' belongs.
(c) Is 'M' a metal or a non-metal.
(d) Write the formula of its chloride.
Study the extract of the Periodic Table given below and answer the questions that follow. Give the alphabet corresponding to the element in question. DO NOT repeat an element. 
The ion of which element will migrate towards the cathode during electrolysis?
What is meant by periodicity of elements?
'In a group, the atomic radii increase with increasing period number', explain this statement and justify it with reference to group 17.
Explain
Size of atom changes when it loses or gain electron
Arrange the following as per the instruction given in the bracket
He,Ar,Ne (Increasing order of the number of electron shells)
Arrange the following as per instruction given in the bracket.
K, Pb, Ca, Zn (increasing reactivity)
Name and state the following with reference to the elements of the first three periods of the periodic table.
Metalloid in Period 3.
The position of certain elements in the Modern Periodic Table is shown below:
| Group → Period ↓ |
1 | 2 | 3 to 12 | 13 | 14 | 15 | 16 | 17 | 18 |
| 1 | G | H | |||||||
| 2 | A | I | B | C | |||||
| 3 | D | E | F |
Using the above table answer the following questions giving reasons in each case:
- Which element will form only covalent compounds?
- Which element is a non-metal with valency 2?
- Which element is a metal with valency 2?
- Out of H, C, and F which has the largest atomic size?
- To which family does H, C, and F belong?
Write the electronic configuration of two elements A and B whose atomic numbers are 20 and 17 respectively. Write the molecular formula of the compound formed when element A reacts with element B. State whether this compound is acidic, basic or neutral. Give a reason to justify your answer.
Name the elements in Period 1.
Name the period which is the shortest period of the periodic table.
Select the correct answer from the options given below.
It is a metal in period 2 having electronic configuration 2, 1?
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 |
