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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
The position of three elements A, B and C in the Periodic Table are shown below –
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Group 16
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Group 17
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A
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B
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C
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(a) State whether A is a metal or non-metal.
(b) State whether C is more reactive or less reactive than A.
(c) Will C be larger or smaller in size than B?
(d) Which type of ion, cation or anion, will be formed by element A?
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.
Name the scientist who first of all showed that atomic number of an element is a more fundamental property than its atomic mass.
Give two example of group 18 elements.
How were the positions of isotopes of an element decided in the modern periodic table?
How does the chemical reactivity of the halogens vary on going in group 17 of the periodic table?
What is the usual number of valence electrons in the atoms of the last element in a period?
How do the atomic radii of elements change as we go from left to right in a period of the periodic table?
Explain why All the elements of a period have different chemical properties.
The following diagram shows a part of the periodic table in which the elements are arranged according to their atomic numbers. (The letters given here not the chemical symbols of the elements):
| a 3 |
b 4 |
c 5 |
d 6 |
e 7 |
f 8 |
g 9 |
h 10 |
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| i 11 |
j 12 |
k 13 |
l 14 |
m 15 |
n 16 |
o 17 |
p 18 |
(i) Which element has a bigger atom, a or f?
(ii) Which element has a higher valency, k or o?
(iii) Which element is more metallic i or k?
(iv) Which element is more non-metallic, d or g?
(v) Select a latter which represents a metal of valency 2.
(vi) Select a letter which represents a non-metal of valency 2.
How does the electronic configuration of an atom relate to its position in the modern periodic table?
Write the number of protons, neutrons and electronic configuration of \[\ce{_19^39K, _15^31P}\]. Also state their position in periodic table.
The electronic configuration of an element T is 2, 8, 8, 1.
What is the period number of T?
Name an alkali metal in period 3 and halogen in period 2.
Name the noble gas with 3 shells.
State the modern periodic law for classification of elements. How many (i) groups and (ii) periods are there in the modern periodic table?
An element E has following electronic configuration:
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K |
L |
M |
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2 |
8 |
6 |
(a) To which group of the periodic table does element E belong?
(b) To which period of the periodic table does element E belong?
(c) State the number of valence electrons present in element E.
(d) State the valency of the element E.
What would be the correct order if Zn, Fe, Al and Cu are arranged in increasing order of reactivity?
How many periods and groups are there in the modern periodic table?
What is meant in the periodic table by a period?
An element A has 2 electrons in its fourth shell. State its electronic configuration.
Answer the following question.
How it can be proved that the basic structure of the Modern Periodic Table is based on the electronic configuration of atoms of different elements?
Define the atomic size.
In the Modern Periodic Table – atoms of all elements are arranged according to their increasing order of – atomic numbers. An atom of nitrogen has seven protons and seven electrons. State what would be its atomic number.
Give the symbol and valency of the following element and radical.
Magnesium
Give the symbol and valency of the following element and radical.
Oxygen [Oxide]
State what the group number in the Modern Periodic Table signifies. Give a reason why elements in the same group, have similar valency and similar chemical properties.
What are the periods in a periodic table?
______ forms the basis of the modern periodic table.
Identify gas A in the following experiment.
What is the symbol of the element Tungsten?
Which of the following elements would lose an electron easily?
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.
Choose an element from period 3 of modern periodic table that matches the description given below in instance. Give a reason for your choice.
It has variable valency and is a member of the Oxygen family (group 16).
Noble gases are placed in the ______ group in the modern periodic table.
Explain giving reason why although the nuclear charge in atoms increases in moving from left to right in a period as well as in moving from top to bottom in a group in the Modern periodic table, but the size of the atoms does not vary similarly in both situations.
Define groups of modern periodic table.
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?
