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प्रश्न
Fill in the blank:
The formulae of chloride of metal M is MCl2. The metal M belongs to ……………. group.
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उत्तर
The formula of the chloride of metal M is MCl2. Metal M belongs to the 2nd group.
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संबंधित प्रश्न
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.
- Calculate the average atomic mass of elements A and C.
- Compare the average atomic mass with atomic mass of B.
- What could the elements A, B and C be?
The elements Be, Mg and Ca each having two electrons in their outermost shells are in periods 2, 3, and 4 respectively of the modern periodic table. Answer the following questions, giving justification in each case:-
(i) Write the group to which these elements belong.
(ii) Name the least reactive element.
(iii) Name the element having largest atomic radius.
The position of eight elements in the Modern Periodic Table is given below where atomic numbers of elements are given in the parenthesis.
| Period No. | ||
| 2 | Li(3) | Be(4) |
| 3 | Na(11) | Mg(12) |
| 4 | K(19) | Ca(20) |
| 5 | Rb(37) | Sr(38) |
(i) Write the electronic configuration of Ca.
(ii) Predict the number of valence electrons in Rb.
(iii) What is the number of shells in Sr?
(iv) Predict whether K is a metal or a non – metal.
(v) Which one of these elements has the largest atom in size?
(vi) Arrange Be, Ca, Mg and Rb in the increasing order of the size of their respective atoms.
How many groups and periods are there in the modern periodic table?
How do the atomic size and metallic character of elements vary as we move?
- down a group and
- from left to right in a period
How does the number of valence electrons vary on moving from left or right in the first period of the periodic table?
Fill in the blank in the following statement:
On moving form right to left in the second period, the number of valency electrons ...............
Explain why, the properties of elements are repeated after 2, 8, 18 and 32 elements in the periodic table.
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 ?
Given alongside is a part of the periodic table. As we move vertically downward from Li to Fr:
| Li | Be |
| Na | |
| K | |
| Rb | |
| Cs | |
| Fr | Ra |
What happens to their metallic character?
Which one of the following does not increase while moving down the group of the periodic table?
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.
no of valence electrons in it
An element X belong to 4th period and 17th group, state.
Write the formula of the compound formed when it reacts with `(27)/(13) y `
An element X belong to 3rd periods and group II of the periodic table state:
the number of valence electrons,
Name the element of lower nuclear charge out of Be and Mg.
What is the common feature of the electronic configuration of the elements at the end of period 2, and period 3?
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.
What will be the valency of an element of atomic number 9 (nine)?
On the basis of electronic configuration, how will you identify the first and the last element of a period?
What is meant by periodicity of elements?
Fill in the blank
Oxidising property ________from fluroine to iodine because the power to accpet electron decreases.
Arrange the following in increasing order of property indicated
SiO2, P2O5, SO3, Cl2O7 (acidic nature)
How could the atomic radius of a noble gas be compared with the other elements in a period?
Consider the section of the periodic table given below:
| Group numbers | IA | IIA | IIIA | IVA | VA | VIA | VIIA | 0 |
| 1 | 2 | 13 | 14 | 15 | 16 | 17 | 18 | |
| Li | D | O | J | Ne | ||||
| A | Mg | E | Si | H | K | |||
| B | C | F | G | L |
Note: In this table B does not represent boron
C does not represent carbon
F does not represent fluorine
H does not represent hydrogen
K does not represent potassium
You must see the position of the element in the periodic table.
Some elements are given in their own symbol and position in the periodic table, while others are shown with a letter. With reference to the table answer the following:
- Which is the most electronegative?
- How many valence electrons are present in G?
- Write the formula of the compound between B and H.
- In the compound between F and J, what type of bond will be formed?
- Draw the electron dot structure for the compound formed between C and K.
Atomic number of an element is 16. State
- the period to which it belongs
- the number of valence electrons
- whether it is a metal or non-metal
Give the number of the group and the period of elements having three shells with three electrons in valence shell.
An element Z has atomic number 16. Answer the following
(a) State the period and group to which Z belongs
(b) Is Z a metal or a non-metal?
(c) State the formula between Z and hydrogen.
(d) what kind of a compund is this?
Arrange the following as per instruction given in the bracket.
Mg, Cl, Na, S, Si (decreasing order of atomic size)
Arrange the following in order of increasing radii:
N, O, P
Write the electronic configuration of element 17T35.
- What is the group number of T?
- What is the period number of T?
- How many valence electrons are there in an atom of T?
- What is the valency of T?
- Is it a metal or non-metal?
- State number of protons and neutrons in T.
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.
Moving left to right in the second period, the number of valence electrons _____.
An element A has 2 electrons in its fourth shell. State:
its valency
The electronic configuration of an element is 2, 8, 4. State it:
name and write its one physical property.
Based on the group valency of element write the molecular formula of the following compound giving justification:
Halide of the elements of group thirteen
