Classification of Elements and Periodicity in Properties MCQ Quiz - Objective Question with Answer for Classification of Elements and Periodicity in Properties - Download Free PDF

Key Points

• Potassium (K) is more reactive than sodium (Na), calcium (Ca), and iron (Fe). Hence, option 2 is correct.
• Reactivity increases down the group in the alkali metals (Group 1 of the Periodic Table).
• Order of reactivity: Potassium > Sodium > Calcium > Iron
• Potassium reacts violently with water, producing potassium hydroxide and hydrogen gas, often with flame or explosion.

Key Points

• Silver (Ag) is one of the least reactive metals and does not easily react with air, water, or most acids. This inertness makes it highly valuable in jewelry and electronics.
• Silver is found in its elemental form in nature and is resistant to corrosion and oxidation under normal conditions, unlike more reactive metals such as magnesium or iron.
• Compared to other metals in the question, such as magnesium (highly reactive) or iron (prone to rusting), silver remains stable and unreactive in most environments.

Additional Information

• Reactivity Series of Metals:
  • Metals are arranged in a reactivity series based on their ability to lose electrons and form positive ions.
  • Highly reactive metals like potassium, sodium, and magnesium are at the top of the series, while less reactive metals like copper, silver, and gold are at the bottom.
• Comparing the Metals in the Question:
  • Silver (Ag): Least reactive; does not corrode or react easily with acids.
  • Magnesium (Mg): Highly reactive; reacts with air and water to form magnesium hydroxide or oxide.
  • Lead (Pb): Moderately reactive; reacts slowly with air and acids but forms protective oxide layers.
  • Iron (Fe): Reacts with oxygen and moisture to form rust (iron oxide).
• Applications of Silver:
  • Silver's low reactivity makes it ideal for use in jewelry, coins, and electronics.
  • Its high conductivity and resistance to corrosion are valuable in electrical contacts and circuits.
  • Despite its inertness, silver's antimicrobial properties are utilized in medical applications such as wound dressings and coatings for medical devices.

The correct answer is Xenon.

Key Points

• Xenon is a noble gas, which is typically found as a monoatomic gas in nature.
• Xenon is chemically inert and does not readily form compounds with other elements.
• It is one of the rare gases found in the Earth's atmosphere, with a concentration of about 0.0000087% by volume.
• Being monoatomic means that Xenon exists as single atoms rather than molecules.

Additional Information

• Noble Gases
  • Noble gases include Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), and Radon (Rn).
  • These gases are characterized by their lack of chemical reactivity due to having complete valence electron shells.
• Monoatomic Gases
  • Monoatomic gases consist of single atoms not bonded to each other.
  • Examples include noble gases like Helium, Neon, and Argon, in addition to Xenon.
• Uses of Xenon
  • Xenon is used in flash lamps, arc lamps, and as a general anesthetic.
  • It is also utilized in ion propulsion systems for spacecraft.
• Chemical Inertness
  • The inertness of noble gases makes them ideal for use in conditions where reactions are undesirable.
  • This property is due to their filled outer electron shells, which make them stable and unreactive.

The correct answer is Oxygen.

Key Points

• Oxygen is a chemical element with the atomic number 8.
• It is represented by the symbol O in the periodic table of elements.
• Oxygen is a highly reactive non-metal and an oxidizing agent that readily forms oxides with most elements and compounds.
• It is essential for most life forms on Earth, as it is a critical component of cellular respiration.
• Oxygen constitutes about 21% of the Earth's atmosphere by volume.
• It is also a part of water (H₂O) and is necessary for combustion processes.
• Oxygen was discovered independently by Carl Wilhelm Scheele and Joseph Priestley in the 1770s.

 Additional Information

•  Hydrogen
  • Hydrogen is the lightest and most abundant element in the universe, with the atomic number 1.
  • It is represented by the symbol H.
  • Hydrogen is primarily found in water (H₂O) and is essential for the formation of many compounds.
• Nitrogen
  • Nitrogen is a chemical element with the atomic number 7.
  • It is represented by the symbol N.
  • Nitrogen makes up about 78% of the Earth's atmosphere and is a crucial component of the biosphere and ecosystems.
• Carbon
  • Carbon is a chemical element with the atomic number 6.
  • It is represented by the symbol C.
  • Carbon is the basis of all known life on Earth, forming the backbone of organic chemistry.

The correct answer is Metalloids.

Key Points

• Metalloids are elements that exhibit properties of both metals and non-metals.
• Boron (B), Silicon (Si), and Germanium (Ge) are commonly classified as metalloids due to their intermediate characteristics.
• Metalloids are typically found along the "stair-step" line of the periodic table that separates metals and non-metals.
• They are semiconductors, which means they conduct electricity under certain conditions, making them valuable in electronics.
• Metalloids often form covalent bonds and have variable oxidation states, contributing to their unique chemical behavior.

Additional Information

• Periodic Table Classification:
  • The periodic table is divided into metals, non-metals, and metalloids based on their physical and chemical properties.
  • Metalloids lie on the dividing line (zigzag pattern) between metals and non-metals, including elements such as Boron, Silicon, Germanium, Arsenic, Antimony, and Tellurium.
• Semiconductors:
  • Metalloids like Silicon and Germanium are widely used as semiconductors in electronic devices such as transistors and integrated circuits.
  • Semiconductors have a conductivity that is between that of conductors (metals) and insulators (non-metals).
• Applications:
  • Boron is used in the production of borosilicate glass and as a doping agent in semiconductors.
  • Silicon is a key material in the electronics industry and is used in solar panels and computer chips.
  • Germanium is used in infrared optics, fiber-optic systems, and as a semiconductor material.
• Characteristics of Metalloids:
  • They often have a metallic appearance but are brittle like non-metals.
  • Metalloids can react differently depending on the substances they interact with, showing metallic or non-metallic chemical behavior.

The correct answer is Zn.

Key Points

• Only a few elements have been found to be absolutely essential for plant growth and metabolism.
• These elements are further divided into two broad categories based on their quantitative requirements: (i) Macronutrients, and (ii) Micronutrients.
• Macronutrients are generally present in plant tissues in large amounts.
  • The macronutrients include carbon (C), hydrogen (H), oxygen (O), nitrogen (N), phosphorous (P), sulphur (S), potassium (K), calcium (Ca) and magnesium (Mg).
  • Of these, carbon, hydrogen and oxygen are mainly obtained from CO₂ and H₂O, while the others are absorbed from the soil as mineral nutrition.
• Micronutrients or trace elements are needed in very small amounts.
  • These include iron, manganese (Mn), copper (Cu), molybdenum (Mo), zinc (Zn), boron (B), chlorine (Cl) and nickel (Ni).

Additional Information

• In addition to the 17 essential elements named above, there are some beneficial elements such as sodium (Na), silicon (Si), cobalt (Co) and selenium (Se). They are required by higher plants

The correct answer is 17th.

• The Halogens are the elements belonging to Group 17 in the periodic table.

• A periodic table is an arrangement of elements based on their atomic numbers and chemical properties.
• It is divided into 18 groups and 7 periods running vertically and horizontally respectively.
• The periodic table accommodates a discrete combination of metal, non-metals, and metalloids.
• The elements in the periodic table are arranged horizontally in ascending order of their atomic numbers known as periods.
• Vertically the elements having identical chemical properties are clubbed together known as groups.
• The 18 groups are also known as columns and the 7 periods are also known as the rows.

Explanation:

Periods:

• Elements are arranged in increasing the atomic number of elements in a period.
• One extra electron gets added to the outermost shell as we move along the periods from left to right.
• The electron gets added to the same shell or orbit and thus the electrons present for bonding increase by one unit.
• Thus, the shell number remains the same but the number of electrons present for bonding increases along a period.

Groups:

• Elements having the same number of outer electrons are put in the same group of the periodic table.
• When we move down a group, new shells get added.
• The outermost shell has electrons present for bonding.
• Though the number of shells increases as we go down in a group, the number of electrons in the outermost shell remains the same.
• For example, the Halogens F, Cl, Br, I, At all belong to group 17 and have 7 electrons in the outermost shell.
• Similarly, Group 16 elements have 6 electrons in the outermost shell, group 15 has 5 electrons in the outermost shell, and so on.

Hence, group 17 is called halogens.

The correct answer is Increases.

Key Points

• The atomic size increases as you go down a group in the periodic table.
• This increase is due to the addition of new electron shells or energy levels.
• As more electron shells are added, the outermost electrons are farther from the nucleus.
• The increased shielding effect from inner electrons also contributes to the larger atomic size.
• This trend of increasing atomic size down a group is observed across the periodic table's elements.

The correct answer is 118.

Key Points

• Modern Periodic Table has 18 Groups and 7 Periods.
• It has 118 Elements.
• The periodic table generally displays only the symbol of the element and not its entire name.
• Each of the tables has a vertical row is called groups.
• Elements in groups have similar chemical and physical properties because they have the same number of outer electrons.
• Each of the tables has horizontal rows is called periods. During a period, a gradual change in chemical properties occurs from one element to another.
• It was given by Dmitri Mendeleev.
• The Modern Periodic table is used to organize all the known elements.

The correct answer is Helium.

Key Points

• The noble gas family has zero valencies.
• The valency of an element is related to how many electrons are in the outer shell.
• The electronic configuration of Helium (He) is 2, 0.
  • Hence, the Valency of the element Helium is 0.
• Neon, Radon, and Argon have zero valencies because they have their outer shell completely filled and are chemically inert gas.

Additional Information

• The combining capacity of an atom is known as its valency.
  • The number of bonds that an atom can form as part of a compound is expressed by the valency of the element.
  • Valence electrons are those electrons that are present in the outermost orbit of the atom.
  • These electrons have a weak attraction towards the atomic nucleus; thus, atoms can easily remove or share these electrons with other atoms.
  • By sharing, gain or donating electrons, chemical bonds are formed between the atoms.
• Lithium has one valency.
• Beryllium has two valencies.
• Fluorine has one valency.

​

The modern periodic table has 18 columns.

Hence the Statement, Modern periodic table has 15 columns is not Correct.

Key Points

The First Periodic Table:

• In the 1860s, a scientist named Dmitri Mendeleev also saw the need to organize the elements.
• He created a table in which he arranged all of the elements by increasing atomic mass from left to right across each row.
• When he placed eight elements in each row and then started again in the next row, each column of the table contained elements with similar properties. He called the columns of elements groups.
• Mendeleev’s table is called a periodic table and the rows are called periods. That’s because the table keeps repeating from row to row, and periodic means “repeating.”

The Modern Periodic Table:

• The modern periodic table is used to organize all the known elements. Elements are arranged in the table by increasing atomic number.
• In the modern periodic table, each element is represented by its chemical symbol. The number above each symbol is its atomic number. Atomic numbers increase from left to right and from top to bottom in the table.
• Rows of the periodic table are called periods. From left to right across a period, each element has one more proton than the element before it.
• Columns of the periodic table are called groups. Elements in the same group have similar properties.
• All elements can be classified into one of three classes: metals, metalloids, or nonmetals. Elements in each class share certain basic properties. From left to right across each period of the periodic table, elements change from metals to metalloids to nonmetals.

The correct answer is Tin.

Important Points

• Silicon, Germanium, Arsenic are metalloids.
• Tin is a metal.

Key Points

The basic difference between Metals, Non-metals, and Metalloids.

The correct answer is Bridge Element.

Explanation:

• Mosley gave the modern Long form of Periodic table where the base of classification was the atomic number.
• According to Mosley's periodic law, the physical and chemical properties of elements are periodic functions of their Atomic number.

• In the long-form periodic table, horizontal rows are called Periods and vertical rows are called groups.
• A diagonal relationship is said to exist between certain pairs of diagonally adjacent elements in the second and third periods (first 20 elements) of the periodic table. 
• These pairs are (lithium (Li) and magnesium (Mg), beryllium (Be), and aluminum (Al), boron (B), and silicon (Si).

• For example, Lithium and magnesium are showing similar properties, so second-period elements are known as Bridge elements.
• Bridge elements are the gap between the alkali and alkali earth metals (groups 1 & 2) on one side and the metalloids/nonmetals (groups 13 - 18) on the other side.
• The third period elements( Na, Mg, Al,Si,P,S,Cl) are called the TYPICAL elements.They are called so because they represent properties of their own group.
• Transition elements refer to elements of d -block in the periodic table because their valencies show transitions.
• Elements belonging to the s- and p-blocks in the periodic table are called the normal elements or main group elements.

 So, Elements of the II^nd period are known as Bridge elements.

The correct answer is 68.

Key Points

• Mendeleev's periodic table
  • Mendeleev published the periodic table in 1869 but not all the elements were discovered by that time, so he left some spaces under Aluminium and Silicon.
  • He examined the relationship between atomic masses and the physical and chemical properties of elements.
  • While preparing the periodic table there were a few instances where he had to place elements with a slightly greater atomic mass before an element with a slightly lower atomic mass as he wanted to place elements with similar chemical properties together.
  • Periodic law states that "properties of elements are periodic function of their atomic masses.​

Additional Information

• By his time only 63 elements were discovered.
• Mendeleev boldly predicted the existence of certain elements that had not been discovered at that time.
• He named them eka-boron, eka-aluminium, and eka-silicon as they have properties similar to that of Boron, Aluminium and Silicon.
• Later on, these names were replaced as follows:
• Eka-boron =Scandium
• Eka-aluminum = gallium
• Eka- silicon = Germanium
• Further, it was observed that the predicted atomic weights of eka-boron (scandium), eka-aluminium (gallium), and eka-silicon (germanium) are 44, 68, 72, and those of calculated weights are 43.8, 70, and 72.6 respectively.
• Eka is a Sanskrit word meaning one.

The correct answer is H, Li, Na, K.
Key Points 

• Elements like H, Li, Na, and K are related to the alkali metal group. 
• The alkali metals consist of the chemical elements lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr).
• Together with hydrogen, they constitute group 1, which lies in the s-block of the periodic table.
• The Group 1 elements are called alkali metals.
•  All the Group 1 elements are very reactive.
• They must be stored under oil to keep air and water away from them.
• Group 1 elements form alkaline solutions when they react with water, which is why they are called alkali metals.

Additional Information

• Modern Periodic table showing Groups and Periods: