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प्रश्न
Write an explanation.
Period
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उत्तर
A period is a horizontal row in the periodic table where elements have the same number of electron shells and show a gradual change in properties across the row.
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संबंधित प्रश्न
Fill in the blank:
The modern periodic table consists of ……………. periods.
How does the metallic character of elements in Modern Periodic Table vary on moving from left to right in a period, and (ii) down a group?Give reason to justify your answer.
Give two example of group 17 elements.
What is the significance of atomic number in the modern classification of elements? Explain with the help of an example.
What is the name of those elements which divide metals and non-metals in the periodic table?
The atomic numbers of four elements P, Q, R and S are 6, 8, 14 and 16 respectively. Out of these, the element known as metalloid is:
(a) P
(b) Q
(c) R
(d) S
Consider the following elements:
Na, Ca, Al, K, Mg, Li
Which of these elements belong to the same group of the periodic table?
How would the tendency to gain electrons change on moving from left to right in a period of the periodic table?
What is the number of valence electrons in the atoms of first elements in a period?
State whether the following statement is true or false:
On going down in a group of the periodic table, the number of valence electrons increases.
On the basis of electronic configuration, how will you identify the first element of a period?
In the modern Periodic Table, why does cobalt with higher atomic mass of 58.93 appear before nickel having lower atomic mass of 58.71?
An element X belongs to 3rd period and group 2 of the periodic table. State:
(a) number of valence electrons
(b) valency
(c) metal or non-metal
(d) name of the element
Name two elements in Inert gas.
Name two elements in each case:
Transition element
Name two elements in each case: Lanthanides
Name the type of elements which have one electron short of octet.
Fill in the blank:
The horizontal rows in the periodic table are called _____________.
An element barium has the atomic number 56. Look up its position in the periodic table and answer the following question.
Is it larger or smaller than caesium (Cs)?
State the modern periodic law for the classification of elements. How many (i) groups and (ii) periods are there in the modern periodic table?
What is the number of elements in the 1st period?
Give the symbol and valency of the following element and radical.
Hydroxide
Answer the following question in one sentence.
The modern periodic table is divided into which blocks?
Right or wrong sentence.
The modern periodic table has 1 to 7 periods.
Right or wrong sentence.
To the left of the zig-zag line in the periodic table are the metal elements.
Distinguish between:
s-block - p-block
“Hydrogen occupies a unique position in Modern Periodic Table”. Justify the statement.
An element X which is a yellow solid at room temperature shows catenation and allotropy. X forms two oxides which are also formed during the thermal decomposition of ferrous sulphate crystals and are the major air pollutants.
- Identify the element X
- Write the electronic configuration of X
- Write the balanced chemical equation for the thermal decomposition of ferrous sulphate crystals?
- What would be the nature (acidic/ basic) of oxides formed?
- Locate the position of the element in the Modern Periodic Table.
Noble gases are placed in the ______ group in the modern periodic table.
A part of modern periodic table is given below. On its basis, answer the following questions:
| Group No. → | 1 | 2 | 13 | 14 | 15 | 16 | 17 | 18 |
| Period ↓ | ||||||||
| 2 | A | B | ||||||
| 3 | E | D | F | C |
Which of the element is a Metalloid?
- Write the electronic configuration of element X, given by its symbol as under: \[\ce{^40_20 X}\]
- Determine its position in the modem periodic table.
- What is the nature of its oxide?
- Name one other element of its group.
Define groups of modern periodic table.
An element ‘M' has 50% of the electrons filled in the 3rd shell as in the 2nd shell. The atomic number of ‘M’ is ______.
Name two elements that you would expect to show chemical reactions similar to calcium. What is the basis of your choice?
Name the metalloids in the first twenty elements.
An element has 2 electrons in its N shell.
State its position in periodic table.
Answer the following in respect of element \[\ce{_16^32S}\].
To which group and period does it belong?
A group of elements in the periodic table is given below (Boron is the first member of the group and Thallium is the last).
Boron, Aluminium, Gallium, Indium, Thallium
Answer the following question in relation to the above group of elements:
If the electronic configuration of aluminium is 2, 8, 3, how many electrons are there in the outer shell of thallium?
