9th Chemistry Periodic Table and Periodicity of Properties Notes from Sindh Board Textbook Exercise
Here are the complete notes prepared from the 9th Chemistry Periodic Table and Periodicity of Properties Notes from Sindh Board Textbook Exercise.
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Here candidates will get the 9th class Chemistry chapter 3 "Periodic Table and Periodicity of Properties" Solved MCQs, Notes, Solved Questions from Textbook Exercise.
Chemistry Class 9 Chapter 3 Periodic Table and Periodicity of Properties Solved MCQs
These are the most repeated 9th class Chemistry Chapter 3 "Periodic Table and Periodicity of Properties" MCQs from the board exams.
01. The elements of the VIIA group are known as:
(a) Lanthanides
(b) Actinides
(c) Halogens ✓
(d) Nobel Gases
02. The atomic number is represented by:
A. A
B. Y
C. X
D. Z ✓
03. 4th and 5th periods in the periodic table are known as:
(a) Short period
(b) Long period ✓
(c) Normal period
(d) Very long period
04. There are ____________ types of solids.
A. 1
B. 2 ✓
C. 6
D. 4
05. Transition Elements are:
(a) All gasses
(b) All metals ✓
(c) All nonmetals
(d) All metalloids
06. Alkali Metals belongs to
(a) 1st Group ✓
(b) 2nd Group
(c) 3rd Group
(d) 4th Group
07. Which one of the following decreases along the period?
(a) Ionization Energy
(b) Atomic Radius ✓
(c) Electronegativity
(d) Electron Affinity
08. The elements of subgroup B are called:
(a) Lanthanides
(b) Actinides
(c) Transition Elements ✓
(d) Alkali Metals
09. Modern Periodic Table was presented by:
(a) H.Mosely ✓
(b) Dobereiner
(c) Mendeleev
(d) Newland
10. In 1864 British chemist Newland put forward the:
(a) Classification of Traids
(b) 8 columns and row arrangements
(c) 9 column shows arrangements
(d) Law of Octaves ✓
11. Atomic Number of Cesium is:
(a) 55 ✓
(b) 65
(c) 75
(d) 85
12. In the Periodic Table, the horizontal lines are called:
(a) Periods
(b) Triads
(c) Groups ✓
(d) Classes
13. The periodic table is divided into S, P, d, and f blocks based on.
(a) Atomic Radius
(b) Electronic Configuration ✓
(c) Ionization Energy
(d) Electron Affinity
14. The ability to attract a shared pair of electrons is called:
(a) Electron Affinity
(b) Electronegativity ✓
(c) Ionization Energy
(d) Shielding Effect
15. The number of electrons in the valence shell of halogens:
(a) 5
(b) 6
(c) 7 ✓
(d) 8
16. How many blocks are there in Modern Periodic Table?
(a) 3
(b) 4 ✓
(c) 5
(d) 6
17. The ability to attract a shared pair of electrons is called:
(a) Electron Affinity
(b) Electronegativity ✓
(c) Ionization Energy
(d) Shielding Effect
18. The elements of Group 1A
(a) Alkali Metals ✓
(b) Alkaline Metals
(c) Noble Gasses
(d) Transition Elements
19. Half of the distance between nuclei of the two bonded atoms is referred to as:
(a) Size
(b) Shielding Effect
(c) Orbit
(d) Atomic Radius ✓
20. According to Mosely the chemical properties of elements are the periodic function of their:
(a) Atomic Size
(b) Atomic Mass
(c) Atomic Radius
(d) Atomic Number ✓
21. In an ionic bond complete ___________ of electrons occurs.
A. Paring
B. Sharing
C. Transfer ✓
D. None
22. They are placed in Zero Group:
(a) Metals
(b) Nonmetals
(c) Noble Gases ✓
(d) Transition Elements
23. Which one is not a property of an electrolytic cell?
A. It consists of one complete cell
B. Anode has +ve charge
C. It converts electrical energy into chemical one
D. Anode has -ve charge ✓
24. Mosely asserts that an element's chemical characteristics are the periodic function of their:
(a) Atomic Size
(b) Atomic Mass
(c) Atomic Radius
(d) Atomic Number ✓
25. He suggested classifying triads, which involved groupings of three elements arranged according to their atomic masses:
(a) Dobereiner ✓
(b) Mendeleev
(c) Newland
(d) Mosely
Chemistry Class 9 Chapter 3 Periodic Table and Periodicity of Properties Short Question Answers
Here are solved short Questions from Class 9 Chemistry Chapter 3 Periodic Table and Periodicity of Properties Sindh Board Textbook Exercise.It includes short question notes of the Periodic Table and Periodicity of Properties from the 9th Class Chemistry Chapter 3 Sindh Board Textbook Exercise.
Here are solved short Questions from Class 9 Chemistry Chapter 3 Periodic Table and Periodicity of Properties Sindh Board Textbook Exercise.
It includes short question notes of the Periodic Table and Periodicity of Properties from the 9th Class Chemistry Chapter 3 Sindh Board Textbook Exercise.
Q.01: Why are noble gases not reactive?
Ans: Noble Gases are non-reactive because noble gases do have 2 or 8 electrons in their valence shells. It means that all the noble gases have their valence shells filled. Their atoms do not have vacant spaces in their valence shell to accommodate extra electrons. Therefore, noble gases do not gain, lose, or share electrons. That is why noble gases are not very reactive.
Q.02: Why does Cesium (atomic no.55) require little energy to release its one electron present in the outermost shell?
Ans: Cesium requires little energy to release its outermost electrons because it has greater atomic size, more shielding effect, and low ionization energy due to which the hold of the nucleus on valence electron is very weak.
Q.03: What is the difference between Mendeleev's periodic law and modern periodic law?
Ans: Here is the main difference between Mendeleev's periodic law and Modern periodic law.
Mendeleev's Periodic Law:
The properties of elements are the periodic function of their atomic masses.
Modern Periodic Law:
The properties of elements are the periodic function of their atomic numbers.
Q.04: How is the periodicity of properties depending upon the number of protons in an atom?
Ans: Chemical properties of elements depend upon electronic configuration which is based upon atomic number or number of protons. So arrangement of elements according to increasing atomic number shows the periodicity of properties.
Q.05: What do you mean by groups and periods in the Periodic Table?
Ans: Here is the main difference between groups and periods in the Periodic Table.
- Group: There are 18 groups in the periodic table and they are studied from top to bottom. The group is defined as "Vertical columns in the periodic table are called groups".
- Period:
- There are 7 periods in the periodic table and they are studied from left to right. The period is defined as "Horizontal rows in the periodic table are called periods".
Q.06: Why the shielding effect of electrons makes cation formation easy?
Ans: The shielding effect of electrons makes the cation formation easy because the electrons present between the nucleus and the outermost shell of an atom, reduce the nuclear charge felt by the electrons present in the outermost shell. The attraction of outer electrons towards the nucleus is partially reduced because of the presence of inner electrons. As a result, an atom experiences less nuclear charge than that of the actual charge. So it makes the cation formation easy.
Q.07: Why and how are elements arranged in the 4th period?
Ans: The elements are arranged in the 4th period because they all have four electronic shells and are arranged by increasing atomic numbers from left to right in the period.
Q.08: Why does the size of an atom not decrease regularly in a period?
Ans: Atomic number increases across a period, so the number of electrons also goes on increasing in the same shell (valence shell). Due to the repulsion of these electrons, the size of atoms increases. That is why there is an irregularity in the size of atoms in a period.
Q.01: Why are noble gases not reactive?
Ans: Noble Gases are non-reactive because noble gases do have 2 or 8 electrons in their valence shells. It means that all the noble gases have their valence shells filled. Their atoms do not have vacant spaces in their valence shell to accommodate extra electrons. Therefore, noble gases do not gain, lose, or share electrons. That is why noble gases are not very reactive.
Q.02: Why does Cesium (atomic no.55) require little energy to release its one electron present in the outermost shell?
Ans: Cesium requires little energy to release its outermost electrons because it has greater atomic size, more shielding effect, and low ionization energy due to which the hold of the nucleus on valence electron is very weak.
Q.03: What is the difference between Mendeleev's periodic law and modern periodic law?
Ans: Here is the main difference between Mendeleev's periodic law and Modern periodic law.
Mendeleev's Periodic Law:
The properties of elements are the periodic function of their atomic masses.
Modern Periodic Law:
The properties of elements are the periodic function of their atomic numbers.
Q.04: How is the periodicity of properties depending upon the number of protons in an atom?
Ans: Chemical properties of elements depend upon electronic configuration which is based upon atomic number or number of protons. So arrangement of elements according to increasing atomic number shows the periodicity of properties.
Q.05: What do you mean by groups and periods in the Periodic Table?
Ans: Here is the main difference between groups and periods in the Periodic Table.
- Group: There are 18 groups in the periodic table and they are studied from top to bottom. The group is defined as "Vertical columns in the periodic table are called groups".
- Period:
- There are 7 periods in the periodic table and they are studied from left to right. The period is defined as "Horizontal rows in the periodic table are called periods".
Q.06: Why the shielding effect of electrons makes cation formation easy?
Ans: The shielding effect of electrons makes the cation formation easy because the electrons present between the nucleus and the outermost shell of an atom, reduce the nuclear charge felt by the electrons present in the outermost shell. The attraction of outer electrons towards the nucleus is partially reduced because of the presence of inner electrons. As a result, an atom experiences less nuclear charge than that of the actual charge. So it makes the cation formation easy.
Q.07: Why and how are elements arranged in the 4th period?
Ans: The elements are arranged in the 4th period because they all have four electronic shells and are arranged by increasing atomic numbers from left to right in the period.
Q.08: Why does the size of an atom not decrease regularly in a period?
Ans: Atomic number increases across a period, so the number of electrons also goes on increasing in the same shell (valence shell). Due to the repulsion of these electrons, the size of atoms increases. That is why there is an irregularity in the size of atoms in a period.
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