Unit 1: Periodic Classification Of Elements And Periodicity

What is Periodic Classification of Elements and Periodicity?

The Periodic Classification of Elements and Periodicity is a fundamental concept in Chemistry that organizes elements based on their properties and periodic trends. This unit introduces the periodic table as a systematic arrangement of elements, highlighting how the table’s structure reflects periodicity in element properties. Students will explore how elements are classified into groups and periods, and understand the significance of periodic trends such as atomic radius, ionization energy, and electron affinity.

Key Topics in Periodic Classification of Elements and Periodicity:

• Periodic Table Organization: Examining the layout of the periodic table, including periods, groups, and the classification of elements into metals, nonmetals, and metalloids.
• Periodic Trends: Understanding how properties such as atomic radius, ionization energy, and electron affinity vary across periods and groups.
• Element Classification: Learning about the characteristics and behavior of different element groups, including alkali metals, alkaline earth metals, transition metals, halogens, and noble gases.
• Periodic Law: Exploring the periodic law and how it states that the properties of elements are a periodic function of their atomic numbers.

Benefits of Studying Periodic Classification of Elements and Periodicity:

• Systematic Understanding: Provides a structured approach to learning about element properties and their relationships.
• Predictive Power: Enhances the ability to predict element behavior and chemical reactivity based on their position in the periodic table.
• Academic Excellence: Prepares students for more advanced Chemistry topics and practical applications in scientific research.

This unit is essential for grasping how elements are systematically categorized and how periodic trends influence their properties. Mastery of these concepts is crucial for a deeper understanding of Chemistry and its applications.

1. Keeping in view the size of atoms, which order is the correct one?

a. Mg > Sr
b. Ba > Mg
c. Lu > Ce
d. Cl > I

2. Mark the correct statement:

a. Na⁺ is smaller than Na atom
b. Na⁺ is larger than Na atom
c. Cl^– is smaller than Cl atom
d. Cl^– ion and Cl atom are equal in size

3. Mark the correct statement:

a. All lanthanides are present in the same group
b. All halogens are present in the same period
c. All alkali metals are present in the same group
d. All noble gases are present in the same period

4. Which statement is incorrect?

a. All the metals are good conductor of electricity.
b. All the metals are good conductor of heat.
c. All the metals form the positive ions.
d. All the metals form acidic oxides.

5. Which statement is correct?

a. Hydrogen resembles in properties with IA, IVA and VIIA elements.
b. Hydrogen resembles in properties with IIIA, IVA and VA elements.
c. Hydrogen resembles in properties with IIA, IVA and VIA elements.
d. Hydrogen resembles in properties with IIA, IIIA and VIIA elements.

6. Mark the correct statement:

a. The ionization energy of calcium is lower than that of barium.
b. The ionization energy of calcium is lower than that of magnesium.
c. The ionization energy of calcium is higher than that of beryllium.
d. The ionization energy of calcium is lower than that of strontium.

7. Mark the correct statement:

a. Electron affinity is a measure of energy required to remove the electron.
b. Electron affinity is a measure of energy released by adding an electron.
c. Electron affinity is a measure of energy required to excite the electron.
d. Electron affinity is a measure of energy released by removing an electron.

8. Mark the correct statement:

a. Metallic character increases down the group.
b. Metallic character increases from left to right along a period.
c. Metallic character remains the same from left to right along a period.
d. Metallic character remains the same down the group.

9. Mark the correct statement:

a. Melting point of halogens is decreased down the group.
b. Melting point of halogens increase down the group.
c. Melting point of halogens remains the same throughout the group.
d. Melting point of halogens first increases and then decrease down the group.

10. Mark the correct statement:

a. Covalent character of metal halides increases from left to right in a period.
b. Boiling point of Group IVA hydrides decreases down the group.
c. Ionic character of hydrides increases from left to right in a period.
d. The basicity of group IIA oxides decreases on descending the group.