Unit 5: Atomic Structure

What is Atomic Structure in Chemistry?

The “Atomic Structure” unit in Chemistry focuses on the fundamental building blocks of matter—atoms. This unit explores the composition of atoms, including their subatomic particles, and the arrangement of these particles within the atom. Understanding atomic structure is crucial for comprehending the behavior of elements and compounds, as well as for predicting chemical reactions and bonding.

Key Topics in Atomic Structure:

• Subatomic Particles: Studying the components of atoms, including protons, neutrons, and electrons, and their roles in defining the properties of elements.
• Atomic Models: Exploring historical and modern models of atomic structure, such as Dalton’s model, Thomson’s model, Rutherford’s model, and Bohr’s model.
• Electron Configuration: Understanding how electrons are arranged in atomic orbitals and how this configuration influences chemical behavior and bonding.
• Quantum Theory: Examining the principles of quantum mechanics that describe the behavior of electrons and the structure of atoms.

Benefits of Studying Atomic Structure:

• Foundational Knowledge: Provides essential insights into the nature of matter and the fundamental principles underlying chemical reactions and properties.
• Predictive Power: Enhances the ability to predict and explain the behavior of elements and compounds based on their atomic structure and electron configuration.
• Scientific Understanding: Develops a deeper understanding of how atomic interactions and bonding lead to the formation of molecules and materials.

Mastering the “Atomic Structure” unit is fundamental for building a solid foundation in Chemistry. This knowledge is essential for understanding more complex concepts and applications in chemistry, including bonding, reactions, and material properties.

1. The nature of positive rays depend on

a. nature of electrode
b. nature of discharge tube
c. nature of residual gas
d. all of above

2. The velocity of photon is

a. independent of its wavelength
b. depends on its wavelength
c. equal to square of its amplitude
d. depends on its source

3. The wave number of the light emitted by a certain source is 2*10⁶ m^-1 .Thw wavelength of this light will be

a. 500nm
b. 500m
c. 200nm
d. 5000000m

4. Rutherford,s model of atom failed because

a. the atom didnot have a nucleus and electrons
b. id did not account for the attraction between protons and neutrons
c. it did not account for the stability of the atom
d. there is actually no space between the nucleus and the electrons

5. Bohr model of atom is contradicted by

a. Plank’s quantum theory
b. dual nature of matter
c. Heisenberg’s uncertainity principle
d. all of the above

6. Splitting of spectral lines when atoms are subjected to strong electric field is called

a. Zeeman effect
b. Stark effect
c. Photoelectric effect
d. Compton effect

7. In the ground state of an atom , the electron is present

a. in the nucleus
b. in the second shell
c. nearest to nucleus
d. farthest from the nucleus

8. Quantum number values for 2p orbitals are

a. n=2 l=1
b. n=1 l=2
c. n=2 l=0
d. n=0 l=1

9. Orbitals having same energy are called

a. hybrid orbitals
b. valence orbitals
c. degenerate orbitals
d. d-orbitals

10. When 6d orbital is complete,the entering electrons goes into

a. 7f
b. 7s
c. 7p
d. 7d