Class 10 Science Chapter 5 MCQ for 2020-2021
Class: 10 | Science |
Chapter: 5 | Multiple Choice Questions (MCQ) Tests |
Class 10 Science Chapter 5 MCQ with Answers
MCQ tests practice for class 10 science is given below. Here, you can practice chapter 5 of class 10 science with important MCQs related to NCERT Textbook. Class 10 Science Chapter 5 MCQs are given below with answers and explanation.
Q1
Which of the following set of elements is written in order of their increasing metallic character?
[A]. Be, Mg, Ca
[B]. Na, Li, K
[C]. Mg, Al, Si
[D]. C, O, N
Answer: Option A
Explanation:Metallic character increases down a group and decreases along a period. Thus, metallic character increases in the order Be, Mg, Ca as they belong to same group.
Q2
The element with atomic number 14 is hard and forms acidic oxide and a covalent halide. To which of the following categories does the element belong?
[A]. Metal
[B]. Metalloid
[C]. Non-metal
[D]. Left-hand side element
Answer: Option C
Explanation:Its outermost shell has 4 electrons. So, it is a non-metal. Non-metal forms acidic oxide and by sharing of electrons with halogen, it forms covalent halide.
Note: Atomic number 14 has electronic configuration 2, 8, 4.
Q3
In a quiz competition, you are asked a question where you have to choose the statement which is/ are incorrect?
[A]. When an element from the left side of the periodic table combines with an element from the right side of the periodic table, ionic bond is formed.
[B]. If two (or more) elements have the same number of valence electrons, then they belong to the different group of the periodic table.
[C]. The atomic number 2 is of helium, thus the element A is inert gas helium.
[D]. When an element from the right side of the periodic table combines with another element from the same side, a covalent bond is formed.
Answer: Option B
Explanation:If two (or more) elements have the same number of valence electrons, then they belong to the same group of the periodic table. For example, if two elements have electronic configurations of 2, 8, 1 and 2, 8, 8, 1, then they have the same number of valence electrons (1 valence electron each), and hence they belong to the same group of the periodic table.
Q4
Read the following sentences carefully, and choose the incorrect one(s):
[A]. The horizontal rows of elements in a periodic table are called periods.
[B]. All other periods start with noble gases like neon, argon, krypton, etc. and end with alkali metals like lithium, sodium, potassium, etc.,
[C]. The elements in a period have consecutive (continuous) atomic numbers.
[D]. The figures 2, 8, 18, 32, etc., representing the maximum number of electrons which can be put in the various shells of the atoms.
Answer: Option B
Explanation:The first period starts with hydrogen and ends with noble gas helium. All other periods start with alkali metals like lithium, sodium, potassium, etc., and end with noble gases like neon, argon, krypton, etc.
Q5
Which one of the following does not increase while moving down the group of the periodic table?
[A]. Atomic radius
[B]. Metallic character
[C]. Valence
[D]. Number of shells in an element
Answer: Option C
Explanation:All the elements of a group of the periodic table have the same number of valence electrons. e.g., all the elements of group 1 have one valence electron each in their atoms.
All the elements of group 18 have 8 valence electrons each in their atoms, except helium which has only 2 valence electrons in its atom. All the remaining three properties increase down the group.
Note: On moving down in a particular group of the periodic table, the number of valence electrons in the elements remains the same. All the remaining three properties increase down the group.
Q6
Which of the following statement is or are correct?
[A]. The period number of an element is equal to the number of electron shells in its atom.
[B]. If two (or more) elements have the same valence shell, then they belong to the same period of the periodic table.
[C]. The group number of an element having up to two valence electrons is equal to the number of valence electrons.
[D]. All the above.
Answer: Option D
Explanation:Here, all the statements are correct. Hence, your answer will be option [D].
Q7
Where would you locate the element with electronic configuration 2, 8 in the Modern Periodic Table?
[A]. Group 8
[B]. Group 2
[C]. Group 18
[D]. Group 10
Answer: Option C
Explanation:Element with electronic configuration 2, 8, is an inert gas i.e., neon and hence, belongs to group 18.
Note: Group 18 elements are known as noble gases or inert gases. They are helium, neon, argon, krypton etc. All the noble gases have 8 electrons in their outermost shell (except helium which has only 2 electrons) in the K valence shell. Thus, the valence shells of all the noble gases are completely filled with electrons.
Q8
Consider the following statements and choose the incorrect one:
[A]. 4th period contains 18 elements. It is called long period.
[B]. 5th period contains 18 elements. It is also a long period.
[C]. 6th period contains 32 elements. It is called very long period.
[D]. None of the above
Answer: Option D
Explanation:Here, all the statements are correct. Hence, your answer will be option [D].
Q9
Which of the following statement(s) about the Modern Periodic Table are incorrect?
[A]. The elements in the Modern Periodic Table are arranged on the basis of their decreasing atomic number.
[B]. The elements in the Modern Periodic Table are arranged on the basis of their decreasing atomic number, the elements in the Modern Periodic Table are arranged on the basis of their increasing atomic masses, Isotopes are placed in adjoining group (s) in the Periodic Table.
[C]. The elements in the Modern Periodic Table are arranged on the basis of their decreasing atomic number, the elements in the Modern Periodic Table are arranged on the basis of their increasing atomic masses, the elements in the Modern Periodic Table are arranged on the basis of their increasing atomic number.
[D]. The elements in the Modern Periodic Table are arranged on the basis of their increasing atomic number.
Answer: Option B
Explanation:All the elements in the modern periodic table are arranged on the basis of their increasing atomic number. All the isotopes can be placed at one place in the same group of the periodic table.
Note: In the modern periodic table or in the long form of the periodic table, the elements are arranged in increasing order of their atomic numbers. This table was prepared by Bohr and is based upon the electronic configuration of elements.
Q10
In a science quiz competition, Simran are asked a question where she had to choose the statement which was/were incorrect?
[A]. The vertical columns in a periodic table are called groups.
[B]. There are 18 groups in the long form of periodic table.
[C]. The elements in a group do not have consecutive atomic numbers.
[D]. The groups 2 and 3, and 13 to 18 contain the normal elements (typical elements or representative elements).
Answer: Option D
Explanation:The groups 1 and 2, and 13 to 17 contain the normal elements (typical elements or representative elements). Group 18 elements are known as noble gases or inert gases. They are helium, neon, argon, krypton, etc. All the noble gases have 8 electrons in their outermost shells (except helium which has only 2 electrons in the K valence shell). Thus, the valence shells of all the noble gases are completely filled with electrons.
why did Mendeléev select Oxygen and Hydrogen to test the chemical properties of elements?
Mendeléev selected hydrogen and oxygen to test the chemical properties of elements as they are very reactive and formed compounds with most elements.
What were the limitations of Mendeleev’s Periodic Law?
1. Isotopes of all elements posed a challenge to Mendeleev’s Periodic Law.
2. The atomic masses do not increase in a regular manner in going from one element to the next. So it was not possible to predict how many elements could be discovered between two elements — especially when we consider the heavier elements.
3. No proper place assigned to Hydrogen.
What is modern periodic law?
The modern periodic law states that Properties of elements are a periodic function of their atomic number.
What happen to atomic radius of atoms when we move from left to right in a period?
The atomic radius decreases in moving from left to right along a period. This is due to an increase in nuclear charge which tends to pull the electrons closer to the nucleus and reduces the size of the atom.
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