Students of ICSE Class 10 should refer to Periodic Properties and Variations of Properties ICSE Class 10 Chemistry board year questions and solutions. below which have come in past board exams. You should always go through questions that have come in previous years. This will help you to understand the pattern of questions in ICSE Class 10 Chemistry and prepare accordingly. This will help you to get better marks in ICSE Class 10 Board Exams
ICSE Class 10 Chemistry Periodic Properties and Variations of Properties Board Exam Questions
Students should learn the important questions and answers given below for Chapter Periodic Properties and Variations of Properties in Chemistry for ICSE Class 10. These board questions are expected to come in the upcoming exams. Students of ICSE Class 10th should go through the below board exams questions and answers which will help them to get more marks in exams.
Board Exam Questions Periodic Properties and Variations of Properties ICSE Class 10 Chemistry
Fill in the blanks in the following statements, with suitable words :
Question: The modern Periodic Table has ……………………. periods.
Answer:
7
Question: Each ……………………. in the Periodic Table is comprised of elements having the same number of electron shells.
Answer:
period
Question: Elements in a period, all have the same number of …………….. in their atoms.
Answer:
electron shells
Question: Elements in a group, all have the same number of ………………. .
Answer:
outer electrons
Question: The most active metals are located in …………… 1 and 2 of the Periodic Table.
Answer:
groups
Question: The most reactive non-metals comprise group …………….. of the Periodic Table.
Answer:
17
Question: The elements of …………….. are known as typical elements.
Answer:
period 3
Question: The elements occupying left and right side groups of Periodic Table are called …………… elements.
Answer:
representative
Question: The rare gases are placed in …………… group at the end.
Answer:
zero
Question: Elements from atomic number 57 to …………… occupy same place in Periodic Table. These elements are called ………………
Answer:
71, lanthanides
Question: Actinides are the elements from atomic number ……………………… to ………….. and are radioactive.
Answer:
89, 103
Question: The actinides and …………… are kept outside the Periodic Table to mark their peculiar properties.
Answer:
lanthanides
Question: The properties of elements are periodic function of their……………….
Answer:
atomic number
Question: The atomic size ……………………… as we move left to right across the period, because the ……………… increases but the ………………… remains the same.
Answer:
decrease, nuclear charge, number of shells
Question: The metallic character ………….. in a group as one moves from top to bottom.
Answer:
increases
Question: The metallic character ………….. in a period as one moves from right to left.
Answer:
decreases
Question: In a period or in a group, the larger the atomic size of an element, the…………………….metallic is the element.
Answer:
more
Question: Moving across a ………………… of the periodic table, the elements show increasing ……………………… character.
Answer:
period, non-metallic
Question: The amount of energy involved in the reaction X + energy → X+ + e– is known as the ………………of the element X.
Answer:
ionization potential
Question: Across a period, the ionization potential………………
Answer:
increases
Question: Down the group, electron affinity……………
Answer:
decreases
Question: The higher the electron affinity of a non-metal, ………………. chemically reactive the nonmetal is.
Answer:
more
Question: The tendency to gain an electron …………….. on moving down a group and ………….. on moving across a period in the Periodic Table.
Answer:
increases; decreases
Question: Elements having high ionization potential have ……………… electron affinities.
Answer:
high
Question: The electronegativity of elements …………. across a period and …………… down a group.
Answer:
increases; decreases
Question: In general, non-metals are ……………….. electronegative than metals.
Answer:
more
Question: On moving from left to right in a given period, the number of shells …………………. .
Answer:
remains the same
Question: Element X belongs to group 2 and period 3 of the Periodic Table. It has ……………….. electrons in the outer most shell.
Answer:
2 (two)
Question: Each period except period 1 in the Periodic Table begins with ……………. and ends up with a …………… .
Answer:
an alkali metal; noble gas
Question: The metallic and non-metallic character depends upon the……………….and……………… of the elements.
Answer:
atomic size, ionization potential
Question: The energy required to remove an electron from a neutral isolated gaseous atom and convert it into a positively charged gaseous ion is called………………
Answer:
ionization potential
Multiple Choice Questions
Question. In the periodic table, alkali metals are placed in the group :
(a) 1
(b) 11
(c) 17
(d) 18
Answer
A
Question. An alkaline earth metal is :
(a) Palarium
(b) Calcium
(c) Lead
(d) Copper
Answer
B
Question. The number of electrons present in the valence shell of halogen is :
(a) 1
(b) 3
(c) 5
(d) 7
Answer
D
Question. If an element A belongs to period 3 and Group II then it will have :
(a) 3 shells and 2 valence electrons
(b) 2 shells and 3 valence electrons
(c) 3 shells and 3 valence electrons
(d) 2 shells and 2 valence electrons
Answer
A
Question. On moving from left to right across a period of the periodic table, the atomic size :
(a) Decreases
(b) Increases
(c) Remains the same
(d) Sometimes increases and sometimes decreases
Answer
A
Question. On moving from left to right across a period of the periodic table, the non-metallic character of the elements :
(a) Decreases
(b) Increases
(c) Remains the same
(d) Depends on the period
Answer
B
Question. On moving from left to right across a period of the periodic table, the ionization potential :
(a) Goes up and down
(b) Decreases
(c) Increases
(d) Remains the same
Answer
C
Question. Ionisation potential increases over a period from left to right because the :
(a) Atomic radius increases and nuclear charge increases
(b) Atomic radius decreases and nuclear charge decreases
(c) Atomic radius increases and nuclear charge decreases
(d) Atomic radius decreases and nuclear charge increases
Answer
D
Question. On moving from left to right across a period of the periodic table, the electron affinity of the elements in groups 1 to 7 :
(a) Goes up and then down
(b) Decreases and then increases
(c) Increases
(d) Decreases
Answer
C
Question. An element in period 3 whose electron affinity is zero :
(a) Neon
(b) Sulphur
(c) Sodium
(d) Argon
Answer
D
Question. Among the period 2 elements, the element which has high electron affinity is :
(a) Lithium
(b) Carbon
(c) Chlorine
(d) Fluorine
Answer
D
Question. On moving from left to right across a period of the periodic table, the electronegativity :
(a) Depends on the number of valence electrons
(b) Remains the same
(c) Decreases
(d) Increases
Answer
D
Question. Among the elements given below, the element with the least electronegativity is :
(a) Lithium
(b) Carbon
(c) Boron
(d) Fluorine
Answer
A
Question. Which of the following would weigh the least ?
(a) 2g atoms of nitrogen
(b) 1 mole of silver
(c) 22·4 litres of oxygen gas at 1 atmospheric pressure and 273 K
(d) 6·02 × 1023 atoms of carbon [Atomic masses : Ag = 108, N = 14, O = 16, C = 12]
Answer
D
Question. The ratio between the number of molecules in 2 g of hydrogen and 32 g of oxygen is :
(a) 1 : 2
(b) 1 : 0·01
(c) 1 : 1
(d) 0·01 : 1 [Given that H = 1, O = 16]
Answer
C
Question: An element with the atomic number 19 will most likely combine chemically with the element whose atomic number is :
(a) 17
(b) 11
(c) 18
(d) 20
Give One Word/Chemical Term
Question. The law that groups elements in family of three.
Answer
Law of triads
Question. The law where every 8th element repeats properties.
Answer
Newland’s Law of Octaves
Question. The law where repetition of properties varies periodically.
Answer
Mendeleev’s Periodic Law
Question. Horizontal arrangement of elements.
Answer
Periods
Question. Vertical arrangement of elements.
Answer
Groups
Question. The elements present in the first period.
Answer
Hydrogen and Helium
Question. The first three alkali metals.
Answer
Lithium, sodium and potassium
Question. Elements with 1, 2 or 3 electrons in the last shell.
Answer
Metals
Question. Elements with 4, 5, 6 or 7 electrons in the last shell.
Answer
Non-metals
Question. Elements with 8 electrons in the last shell.
Answer
Rare gases
Question. Elements where the penultimate shell is being filled with electrons.
Answer
Transitional metals
Question. A non-metal which has three electrons in the outermost shell.
Answer
Gallium
Question. The largest atom in the third period.
Answer
Sodium
Question. The smallest atom in the third period.
Answer
Chlorine
Question. The most metallic element in the third period.
Answer
Sodium
Question. The most non-metallic element in the third period.
Answer
Chlorine
Question. The element which is the most electronegative in the third period.
Answer
Chlorine
Question. Most active non-metal.
Answer
Fluorine
Question. A metal which is a liquid at room temperature.
Answer
Mercury
Question. A liquid non-metal.
Answer
Bromine
Question. The transition element whose electronic configuration does not agree with the general pattern.
Answer
Palladium
Question. The element with the least ionization potential in the third period.
Answer
Sodium
Question. The amount of energy released when an atom in the gaseous state accepts an electron to form an anion.
Answer
Electron affinity
Question. The element which has the highest electron affinity in the third period.
Answer
Chlorine
Question. The electrons present in the outermost shell of an atom.
Answer
Valence electrons
Define/Explain the Following
1. Typical elements.
The elements of the third period (Na, Mg, Al, Si, P, S, Cl, Ar) are called the typical elements. Each of these elements represent the general properties of all the elements of its group.
2. Transition elements.
The elements which possesses partially filled d-orbital in its penultimate shell are called transition elements.
3. Actinides
The 15 elements beginning with actinium and have atomic numbers 89 to 103 are called actinides.
4. Rare earths.
The sixth period has 15 elements with atomic numbers 57 to 71 (La-Lu), beginning with lanthanum. These 15 elements are very much alike chemically and are known as rare earths or lanthanides.
5. Transuranium elements.
The elements beyond uranium U, in the seventh period are called transuranium elements. These elements do not occur naturally. They all have been prepared artificially.
6. Bridge elements
The elements of second period are called bridge elements because they connect their own group elements with the elements of next group lying diagonally to them in the periodic
table e.g., Li (Lithium) and Mg (Magnesium).
7. Ionization potential
It is the amount of energy required to remove an electron from the outer most (valence) shell of an isolated gaseous atom.
8. Electron affinity
It is the amount of energy released when an electron is added to the outer most (valence) shell of an isolated gaseous atom.
Reasoning Based Questions
Q. 1. Explain why the elements placed in the same group of the periodic table have the same chemical properties ?
Answer
Elements placed in the same group of the periodic table have the same chemical properties because they have the same number of valence electrons in the outermost shell of their atoms.
Q. 2. Why group IA elements are called alkali metals ?
Answer
Group IA elements are called alkali metals because their hydroxides are soluble in water and form strong bases.
Q. 3. Why sodium is a metal while sulphur is a non-metal ?
Answer
Sodium has a larger atomic radii and lower ionization potential than sulphur. Hence sodium is a metal while sulphur is a non metal.
Q. 4. Alkali metals are good reducing agents.
Answer
Alkali metals are good reducing agents because alkali metals have one valence electron which they lose to attain stability. Hence, they themselves undergo oxidation causing reduction of others and are good reducing agents.
Q. 5. Why are the elements sodium and chlorine in the same period of the periodic table ?
Answer
Elements sodium and chlorine are in the same period of the periodic table because the atoms of both the elements have three shells containing the electrons.
Q. 6. Sodium atom, Na forms the positive ion Na+, but chlorine atom Cl, does not form the positive Cl+ ion.
Answer
Sodium is the first element of period 3 whereas chlorine is the last but one element of the same period. Since ionization potential increases across a period, the ionization potential of Na is much smaller than that of Cl. Hence, Na can lose an electron to form Na+ ion whereas Cl cannot lose an electron to form Cl+ ion.
Q. 7. Potassium atom is larger than sodium atom. Why ?
Answer
Potassium is placed below sodium in group 1. It, therefore has one more electron shell. Na atom has three electron shells (2, 8, 1); K atom has four (2, 8, 8, 1). So, potassium atom is bigger than sodium atom.
Q. 8. Magnesium atom is smaller than calcium atom. Why ?
Answer
Magnesium atom precedes calcium atom in the same group, i.e., group 2. Magnesium atom has got three electron shells (2, 8, 2) whereas calcium atom has four electron shells (2, 8, 8, 2). So, calcium atom is larger than the sodium atom.
Q. 9. Magnesium atom is smaller than sodium atom. Why ?
Answer
Magnesium come after sodium in the same period. Atoms of both elements have three electron shells (Na : 2, 8, 1 : Mg : 2, 8, 2). But the nuclear charge of sodium is + 11 and that of magnesium is + 12. Hence, the electron shells are pulled inward more strongly in Mg atom than in Na atom. Hence, Mg atom is smaller than Na atom.
Q. 10. Which is larger Na+ or K+ ? Why ?
Answer
K+ is larger than Na+ because the ionic radius increases in a particular group on moving from top to bottom due to increase in the principle energy shell though the number or electrons in the valence shell remain the same.
Short Questions
Q. 1. State Newland’s law of octaves. Why did the law of octaves fail ? Write three important drawbacks of Newland’s classification.
Answer
Newland’s law of octaves : The elements with similar properties occur each time after every seven elements. Just the same way as the repetition of musical node in a octave.
The law failed because of the following reasons :
(i) The law was applicable only upto calcium. It could not include the other elements beyond calcium.
(ii) With the discovery of rare gases, it was the ninth element and not the eighth element having similar chemical properties.
Drawbacks of Newland’s classification :
(i) Newland did not gave any place to transition elements.
(ii) Atomic weights were not correctly estimated.
(iii) Certain elements did not fit into the scheme.
Q. 2. Answer the following questions regarding Mendeleev’s modified periodic table.
Answer
(i) How many periods are there in Mendeleev’s periodic table ?
(ii) How many groups are there in Mandeleev’s periodic table ?
(iii) How many groups consist of normal elements and transitional elements in Mendeleev’s periodic table ?
(iv) Which group of elements was missing from Mendeleev’s original periodic table ?
(v) What is the number of first and last vertical column ?
(vi) In which vertical column hydrogen is placed.
(vii) What are horizontal rows known as ? How many are they in number ?
(viii) How many elements are there in the first horizontal row ?
(ix) How many elements are there in the second and third horizontal rows each ?
Ans. (i) There are seven periods in Mendeleev’s periodic table.
(ii) There are nine groups, numbered from 0 to 8.
(iii) The groups IA, IIA, IIIA, IVA, VA, VIA and VIIA consist normal elements and groups,
IIIB, IVB, VB, VIB, VIIB and IB, IIB consist of transition elements.
(iv) Zero group (Noble gases).
(v) The first column is numbered zero, whereas last group is numbered 8.
(vi) Hydrogen is placed in IA group.
(vii) The horizontal rows in periodic table are known as periods. There are seven periods in all.
(viii) There are only two elements in the first period.
(ix) The second and third periods have eight elements each.
Q. 3. What is modern periodic law ? Name the elements of ‘first transition series’.
Answer
The modern periodic law states that, “The properties of elements are the periodic functions of their electronic configuration”. Scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc.
Q. 4. Who gave modern periodic law ? What is meant by a group in the periodic table ?
Answer
Henry Moseley gave the modern periodic law. Vertical column in a periodic table are called groups.
Q. 5. How many vertical columns are there in the modern periodic table ? State whether the ionization potential increases or decreases on going down a group.
Answer
18 vertical columns are there in the modern periodic table. Ionization potential decreases on going down a group.
Q. 6. How many elements are in the second period of modern periodic table ? Write the names of first and last elements of second period.
Answer
There are eight elements in the second period of the periodic table. Lithium (Li) and neon (Ne) are the first and last element of the second period.
Q. 7. How many elements are in the third period of modern periodic table ? Write the names of first and last elements of third period.
Answer
Eight elements in the third period of the periodic table. Sodium (Na) and Argon (Ar) are the first and last elements of the third period.
Q. 8. How many elements are in the fourth, fifth and sixth period of modern periodic table ?
Answer
There are 18, 18 and 32 elements in the fourth, fifth and sixth period of the periodic table respectively.
Q. 9. Which period is the shortest one ? In which period maximum number of elements are present ?
Answer
The first period is the shortest period in the periodic table as it has only two elements i.e., H and He. The period in which the maximum number of elements are present is 6th period. It is the longest period of the periodic table as it has 32 elements.
Q. 10. Give the number of the group and the period, of the element having three shells with three electrons in valence shell.
Answer
The element having three shells with three electrons in valence shell belong to 13th group and 3rd period.
Q. 11. What are the main characteristic of the last elements in the periodic table ? What is the general name given to such elements ?
Answer
The main characteristic of the last elements in the periods is the presence of 8 electrons in their valence shell (i.e., octet is complete). The general name of such elements are noble gases or inert gases.
Q. 12. What are typical elements ? Give the ‘liquid elements’ in periodic table.
Answer
Na, Mg, Al, Si, P, S, Cl, Ar are the elements present in third short period in periodic table.
These elements are known as typical elements. Francium, mercury and bromine are known as liquid elements.
