Question
CHEM 301, Midterm Study questions
Part-I: Cycle the letter that bears the correct answer, and absolutely no double cycling or dirty work!
1. An excited H atom emits light with a frequency of 1.141x1014s
-1
to reach the n=4 energy
level. In what principle quantum number did the electron originally reside?
a. n=1 b. n=2 c. n=5 d. n=6 e. none
2. Which one of the formulas for ionic compound below is incorrect?
a. n =SrCl2 b. Cs2S c. AlCl3 d. Al3P2 e. CaSe
3. Which is classified as nonpolar covalent? a. The H-I bond in HI b. the H-S bond in H2S
c. the P-Cl bond in PCl3 d. the N-Cl bond in NCl3 e. the N-H bond in NH3
4. What is the total number of electrons in the correct Lewis dot formula of the sulfite ion?
a. 8 b. 24 c. 26 d. 30 e. 32
5. Which one the of the following violates the octet rule? a. PCl3 b. CBr4 c. NF3 d. OF2 e.
AsF5
6. Draw one of the resonance structures of SO3 . The formal charge of S is
a. +2 b. +1 c. 0 d. -1 e. -2
7. In the Lewis structure for the OF2 molecule, the number of lone pairs of electrons around
the central oxygen atom is a. 0 b. 1 c. 2 d. 3 e. 4
8. Formed by the attraction between metal atoms and a "sea" of delocalized electrons.
a. Metallic bond b. Hydrogen bond c. polar covalent d. non-polar e. none
9. Is a measure of an atom's ability to attract electrons in a chemical bond? a.
Electronegativity b. electrostatic force c. dipole-dipole d. van der waal e. none
10. The valence electrons of representative elements are
a. in s orbitals only b. located in the outermost occupied major energy level c. located
closest to the nucleus d. located in d orbitals e. located in the innermost occupied shell
e. none
11. With regard to the species 16O
2-
,
19F
- and 20Ne, which of the following statements
is correct? a. All three species contain 10 electrons b. The sum of the neutrons in all
three species is 27 c. The sum of the protons in all three species is 28 d.
Both 19F
- and 20Ne contain 20 neutrons e. none of the above
12. Which of the following does not have a noble gas electron configuration? (or Which of
the following is not isoelectronic with a noble gas?)
a. S2-
b. Ba+
c. Al3+ d. Sb3-
e. Sc3+
13. Which one of the formulas for ionic compounds below is incorrect?
a. SrCl2 b. Cs2S c. AlCl3 d. Al3P2 e. CaSe
14. Which one of the following violates the octet rule?
a. PCl3 b. CBr4 c. NF3 d. OF2 e. AsF5
15. Draw one of the resonance structures of SO3. The formal charge of S is
a. +2 b. +1 c. 0 d. -1 e. -2
16. Consider the bicarbonate ion (also called the hydrogen carbonate ion). After drawing the
correct Lewis dot structure(s), you would see:a. two double bonds around the central carbon atom b. three single bonds around the
central carbon atom c. four single bonds around the central carbon atom d. two
equivalent resonance forms e. three equivalent resonance forms.
17. The electronic structure of the SO2 molecule is best represented as a resonance hybrid of
____ equivalent structures.
a. 2 b. 3 c. 4 d. 5 e. This molecule does not exhibit resonance.
18. In the Lewis structure for the OF2 molecule, the number of lone pairs of electrons around
the central oxygen atom is
a. 0 b. 1 c. 2 d. 3 e. 4
19. What is the total number of electrons in the correct Lewis dot formula of the sulfite ion?
a. 8 b. 24 c. 26 d. 30 e. 32
20. The correct dot formulation for nitrogen trichloride has:
a. 3 N-Cl bonds and 10 lone pairs of electrons . b. 3 N=Cl bonds and 6 lone pairs of
electrons c. 1 N-Cl bond, 2 N=Cl bonds and 7 lone pairs of electrons.
d. 2 N-Cl bonds, 1 N=Cl bond and 8 lone pairs of electrons e. 3 N-Cl bonds and 9 lone pairs
of electrons.
21. The correct electron-dot formulation for hydrogen cyanide shows:
a. 2 double bonds and two lone pairs of electrons on the N atom.
b. 1 C-H bond, 1 C=N bond, 1 lone pair of electrons on the C atom and 1 lone pair of
electrons on the N atom.
c. 1 C-H bond, 1 C-N bond, 2 lone pairs of electrons on the C atom and 3 lone pairs of
electrons on the N atom.
d. 1 triple bond between C and N, 1 N-H bond and 2 lone pairs of electrons on the C atom.
e. 1 triple bond between C and N, 1 C-H bond and 1 lone pair of electrons on the N atom.
22. Which of the following pair has same geometry?
a. CH4 and SF4 b. NH4
+ and XeF4 c. CH4 and NH4
+
d. More than one of the above e.
none of the above
23. Is form when orbitals of two atoms overlap and the overlap region, which is between the
nuclei, is occupied by a pair of electrons. a Molecular Orbital Theory b. Ionic bond c.
Collision Theory d. Valance Bond Theory d. none of the above
24. What is the hybridization of oxygen in water?
a. SP b. SP2
c. SP3
d. SP3d e. none
25. What is the molecular geometry of H2S?
a. Tetrahedral b. trigonal planar c. Linear d. Bent e. none
26. What is the bond angle in the ideal structure of octahedral?
a. 109.5° b. 120° c. 180° d. 90° e. none
27. Which of the following is an exception to the octet rule.
a. CO2 b. CNO c. CO d. H2O e. NO
Part II: Predict whether each compound is purely covalent, purely ionic or polar covalent.
28. RbCl _______________________ 27. S8 __________________________
29. TiCl2 _________________________ 28. SbCl3 _______________________
30. LiI ___________________________ 29. Br2 _________________________
Part III: Appropriately Answers all questions correctly, absolutely on dirty work.
30. Draw the molecular shapes and predict the bond angles (relative to the ideal angles) of
a. BCl2 ( AX2 ) b. NO3
- and CH2O (AX3) c. SO2 and SnCl2 (AX2E) d. CH4 and ClO4
-
(AX4)
e. NH3 and PF3 (AX3E) f. H2O and SCl2 (AX2E2)
g. PF5 and SOF4 (AX5) h. SF4 and IO2F2
-
(AX4E) i. ClF3 and BrF3 (AX3E2) j. XeF2 and I3
-
(AX2E3) k. IOF5 (AX6) l. BrF5 and TeF5
-
(AX5E ) m. XeF4 and ICl4
-
(AX4E2)z
31. Find the formal charge for each atoms in the above part-III #1 b, m, g, c, d, h, a, I, I, j
32. Calculate the energy required to remove the electron from a hydrogen atom in its ground state.
33. Find the formal charge for each atom in the following; a. NO b. HPO4
2-
and H2PO4
-
c.
SO4
2-
34. Calculate the energy required to excite the hydrogen electron from level n = 1 to level n = 2.
Also calculate the wavelength of light that must be absorbed by a hydrogen atom in its ground
state to reach this excited state.
35. A hydrogen atom absorbs a photon of visible light, and its electron enters the n = 4 energy
level. Calculate a). the change in energy of the atom and b). the wavelength (in nm) of the
photon.
36. A hydrogen atom with its electron in n = 6 energy level emits a photon of IR light. Calculate
a). the change in energy of the atom and b). the wavelength (in angstroms)
37. An excited hydrogen atom emits light with a frequency of 1.141 x 1014 s
-1
as its electron moves
from one energy level to the energy level for which n = 4. (a) Calculate the energy change of
the electron. (b) In what energy level did it begin?
38. What amount of energy is emitted when the electron of an excited hydrogen atom falls from
the 3rd energy level to the energy level closest to the nucleus?
39. Calculate the number of neutron, proton and electron below
a. 13 Al+3
b. 15 P
-3
40. An element Z has three naturally occurring isotopes. One of the isotopes has a mass of 20amu
and an abundance of 90.48%. A second isotope has a mass of 21amu and an abundance of 0.27%.
A third has a mass of 22amu and an abundance of 9.25%. Calculate the relative atomic mass of Z
41. Calculate the frequency and energy corresponding to the 4th line in the Balmer series of the hydrogen
spectra.
42. A line in the Balmer series of emission lines of excited H atoms has a wavelength of 410.17nm.
To what value of n does this correspond?
3. Calculate the wavelength of the first line in the Lyman series.
44. Calculate the De-broglie wavelength of an electron with a velocity of 1x106m/s, where the
electron mass is 9.11x10-31kg. ( h= 6.626x10-34Kg.m2
/s )
45. Calculate the wavelength and frequency of the third line in the paschen series of hydrogen.
46. An AM radio brocasts at 70.1kiloherte. What is the wavelength of the radio wave in meter and
energy?
47. State the modern atomic theory.
48. Briefly explain chemical bonding and its type with one example each.
49. Briefly explain intermolecular forces and tell which type of chemical bond they exist in with one
example each.
50. Explain the absorption and emission spectra of the hydrogen atom.
51. Explain how electron exhibit the wave-particle duality nature of light.
52. Briefly example the electric and magnetic field of light, amplitude, crest, trough, frequency, and
wavelength.
53. Explain the Bohr and Schrodinger model of the atom.
Part-I: Cycle the letter that bears the correct answer, and absolutely no double cycling or dirty work!
1. An excited H atom emits light with a frequency of 1.141x1014s
-1
to reach the n=4 energy
level. In what principle quantum number did the electron originally reside?
a. n=1 b. n=2 c. n=5 d. n=6 e. none
2. Which one of the formulas for ionic compound below is incorrect?
a. n =SrCl2 b. Cs2S c. AlCl3 d. Al3P2 e. CaSe
3. Which is classified as nonpolar covalent? a. The H-I bond in HI b. the H-S bond in H2S
c. the P-Cl bond in PCl3 d. the N-Cl bond in NCl3 e. the N-H bond in NH3
4. What is the total number of electrons in the correct Lewis dot formula of the sulfite ion?
a. 8 b. 24 c. 26 d. 30 e. 32
5. Which one the of the following violates the octet rule? a. PCl3 b. CBr4 c. NF3 d. OF2 e.
AsF5
6. Draw one of the resonance structures of SO3 . The formal charge of S is
a. +2 b. +1 c. 0 d. -1 e. -2
7. In the Lewis structure for the OF2 molecule, the number of lone pairs of electrons around
the central oxygen atom is a. 0 b. 1 c. 2 d. 3 e. 4
8. Formed by the attraction between metal atoms and a "sea" of delocalized electrons.
a. Metallic bond b. Hydrogen bond c. polar covalent d. non-polar e. none
9. Is a measure of an atom's ability to attract electrons in a chemical bond? a.
Electronegativity b. electrostatic force c. dipole-dipole d. van der waal e. none
10. The valence electrons of representative elements are
a. in s orbitals only b. located in the outermost occupied major energy level c. located
closest to the nucleus d. located in d orbitals e. located in the innermost occupied shell
e. none
11. With regard to the species 16O
2-
,
19F
- and 20Ne, which of the following statements
is correct? a. All three species contain 10 electrons b. The sum of the neutrons in all
three species is 27 c. The sum of the protons in all three species is 28 d.
Both 19F
- and 20Ne contain 20 neutrons e. none of the above
12. Which of the following does not have a noble gas electron configuration? (or Which of
the following is not isoelectronic with a noble gas?)
a. S2-
b. Ba+
c. Al3+ d. Sb3-
e. Sc3+
13. Which one of the formulas for ionic compounds below is incorrect?
a. SrCl2 b. Cs2S c. AlCl3 d. Al3P2 e. CaSe
14. Which one of the following violates the octet rule?
a. PCl3 b. CBr4 c. NF3 d. OF2 e. AsF5
15. Draw one of the resonance structures of SO3. The formal charge of S is
a. +2 b. +1 c. 0 d. -1 e. -2
16. Consider the bicarbonate ion (also called the hydrogen carbonate ion). After drawing the
correct Lewis dot structure(s), you would see:a. two double bonds around the central carbon atom b. three single bonds around the
central carbon atom c. four single bonds around the central carbon atom d. two
equivalent resonance forms e. three equivalent resonance forms.
17. The electronic structure of the SO2 molecule is best represented as a resonance hybrid of
____ equivalent structures.
a. 2 b. 3 c. 4 d. 5 e. This molecule does not exhibit resonance.
18. In the Lewis structure for the OF2 molecule, the number of lone pairs of electrons around
the central oxygen atom is
a. 0 b. 1 c. 2 d. 3 e. 4
19. What is the total number of electrons in the correct Lewis dot formula of the sulfite ion?
a. 8 b. 24 c. 26 d. 30 e. 32
20. The correct dot formulation for nitrogen trichloride has:
a. 3 N-Cl bonds and 10 lone pairs of electrons . b. 3 N=Cl bonds and 6 lone pairs of
electrons c. 1 N-Cl bond, 2 N=Cl bonds and 7 lone pairs of electrons.
d. 2 N-Cl bonds, 1 N=Cl bond and 8 lone pairs of electrons e. 3 N-Cl bonds and 9 lone pairs
of electrons.
21. The correct electron-dot formulation for hydrogen cyanide shows:
a. 2 double bonds and two lone pairs of electrons on the N atom.
b. 1 C-H bond, 1 C=N bond, 1 lone pair of electrons on the C atom and 1 lone pair of
electrons on the N atom.
c. 1 C-H bond, 1 C-N bond, 2 lone pairs of electrons on the C atom and 3 lone pairs of
electrons on the N atom.
d. 1 triple bond between C and N, 1 N-H bond and 2 lone pairs of electrons on the C atom.
e. 1 triple bond between C and N, 1 C-H bond and 1 lone pair of electrons on the N atom.
22. Which of the following pair has same geometry?
a. CH4 and SF4 b. NH4
+ and XeF4 c. CH4 and NH4
+
d. More than one of the above e.
none of the above
23. Is form when orbitals of two atoms overlap and the overlap region, which is between the
nuclei, is occupied by a pair of electrons. a Molecular Orbital Theory b. Ionic bond c.
Collision Theory d. Valance Bond Theory d. none of the above
24. What is the hybridization of oxygen in water?
a. SP b. SP2
c. SP3
d. SP3d e. none
25. What is the molecular geometry of H2S?
a. Tetrahedral b. trigonal planar c. Linear d. Bent e. none
26. What is the bond angle in the ideal structure of octahedral?
a. 109.5° b. 120° c. 180° d. 90° e. none
27. Which of the following is an exception to the octet rule.
a. CO2 b. CNO c. CO d. H2O e. NO
Part II: Predict whether each compound is purely covalent, purely ionic or polar covalent.
28. RbCl _______________________ 27. S8 __________________________
29. TiCl2 _________________________ 28. SbCl3 _______________________
30. LiI ___________________________ 29. Br2 _________________________
Part III: Appropriately Answers all questions correctly, absolutely on dirty work.
30. Draw the molecular shapes and predict the bond angles (relative to the ideal angles) of
a. BCl2 ( AX2 ) b. NO3
- and CH2O (AX3) c. SO2 and SnCl2 (AX2E) d. CH4 and ClO4
-
(AX4)
e. NH3 and PF3 (AX3E) f. H2O and SCl2 (AX2E2)
g. PF5 and SOF4 (AX5) h. SF4 and IO2F2
-
(AX4E) i. ClF3 and BrF3 (AX3E2) j. XeF2 and I3
-
(AX2E3) k. IOF5 (AX6) l. BrF5 and TeF5
-
(AX5E ) m. XeF4 and ICl4
-
(AX4E2)z
31. Find the formal charge for each atoms in the above part-III #1 b, m, g, c, d, h, a, I, I, j
32. Calculate the energy required to remove the electron from a hydrogen atom in its ground state.
33. Find the formal charge for each atom in the following; a. NO b. HPO4
2-
and H2PO4
-
c.
SO4
2-
34. Calculate the energy required to excite the hydrogen electron from level n = 1 to level n = 2.
Also calculate the wavelength of light that must be absorbed by a hydrogen atom in its ground
state to reach this excited state.
35. A hydrogen atom absorbs a photon of visible light, and its electron enters the n = 4 energy
level. Calculate a). the change in energy of the atom and b). the wavelength (in nm) of the
photon.
36. A hydrogen atom with its electron in n = 6 energy level emits a photon of IR light. Calculate
a). the change in energy of the atom and b). the wavelength (in angstroms)
37. An excited hydrogen atom emits light with a frequency of 1.141 x 1014 s
-1
as its electron moves
from one energy level to the energy level for which n = 4. (a) Calculate the energy change of
the electron. (b) In what energy level did it begin?
38. What amount of energy is emitted when the electron of an excited hydrogen atom falls from
the 3rd energy level to the energy level closest to the nucleus?
39. Calculate the number of neutron, proton and electron below
a. 13 Al+3
b. 15 P
-3
40. An element Z has three naturally occurring isotopes. One of the isotopes has a mass of 20amu
and an abundance of 90.48%. A second isotope has a mass of 21amu and an abundance of 0.27%.
A third has a mass of 22amu and an abundance of 9.25%. Calculate the relative atomic mass of Z
41. Calculate the frequency and energy corresponding to the 4th line in the Balmer series of the hydrogen
spectra.
42. A line in the Balmer series of emission lines of excited H atoms has a wavelength of 410.17nm.
To what value of n does this correspond?
3. Calculate the wavelength of the first line in the Lyman series.
44. Calculate the De-broglie wavelength of an electron with a velocity of 1x106m/s, where the
electron mass is 9.11x10-31kg. ( h= 6.626x10-34Kg.m2
/s )
45. Calculate the wavelength and frequency of the third line in the paschen series of hydrogen.
46. An AM radio brocasts at 70.1kiloherte. What is the wavelength of the radio wave in meter and
energy?
47. State the modern atomic theory.
48. Briefly explain chemical bonding and its type with one example each.
49. Briefly explain intermolecular forces and tell which type of chemical bond they exist in with one
example each.
50. Explain the absorption and emission spectra of the hydrogen atom.
51. Explain how electron exhibit the wave-particle duality nature of light.
52. Briefly example the electric and magnetic field of light, amplitude, crest, trough, frequency, and
wavelength.
53. Explain the Bohr and Schrodinger model of the atom.
Answers
Answered by
GPT-4o mini
### Part I: Multiple Choice
1. **(e)** none
2. **(d)** Al3P2
3. **(a)** The H-I bond in HI
4. **(a)** 8
5. **(e)** AsF5
6. **(c)** 0
7. **(c)** 2
8. **(a)** Metallic bond
9. **(a)** Electronegativity
10. **(b)** located in the outermost occupied major energy level
11. **(a)** All three species contain 10 electrons
12. **(e)** Sc3+
13. **(d)** Al3P2
14. **(e)** AsF5
15. **(c)** 0
16. **(d)** two equivalent resonance forms
17. **(b)** 3
18. **(c)** 2
19. **(a)** 8
20. **(e)** 3 N-Cl bonds and 9 lone pairs of electrons
21. **(e)** 1 triple bond between C and N, 1 C-H bond and 1 lone pair of electrons on the N atom.
22. **(c)** CH4 and NH4+
23. **(d)** Valence Bond Theory
24. **(c)** SP3
25. **(d)** Bent
26. **(d)** 90°
27. **(e)** NO
### Part II: Type of Bonding
28. RbCl **Ionic**
29. TiCl2 **Polar covalent** (partly ionic)
30. LiI **Ionic**
31. SbCl3 **Polar covalent**
32. Br2 **Purely covalent**
### Part III: Answer with Explanation
For drawing molecular shapes, predicting bond angles, and calculating formal charges, manual work or diagrams will be needed. Here is how to approach a selection of the problems.
### Example for 30a: BCl2 (AX2)
- **Shape**: Linear
- **Bond Angles**: 180°
### Formal Charge Calculation Example for 31:
**a. NO**
- Formal Charge(N) = 5 - (0 + 1/2 * 2) = 4 - 1 = **3**
- Formal Charge(O) = 6 - (4 + 1/2 * 2) = 6 - 5 = **1**
**b. HPO4^2-**
- Formal Charge for H = 1 - 0 = **0**
- Formal Charge for P = 5 - (0 + 1/2 * 8) = 5 - 4 = **1**
- Formal Charge for O = 6 - (6 + 1/2 *(8)) = 6 - 8 = **-2**
### Energy Calculations
For calculations such as those presented in 32, 34, and 36, use the formula:
\[
E = -R_H \left( \frac{1}{n^2_{final}} - \frac{1}{n^2_{initial}} \right)
\]
Where \( R_H = 2.18 \times 10^{-18} \text{ J} \).
### Wavelength Calculations
Using the relationship:
\[
\lambda = \frac{hc}{E}
\]
Where:
- \( h = 6.626 \times 10^{-34} \text{ J·s} \)
- \( c = 3.00 \times 10^8 \text{ m/s} \)
### Modern Atomic Theory and Chemical Bonding
- **Modern Atomic Theory**: Atoms consist of a nucleus made of protons and neutrons, surrounded by electrons in specific energy levels.
- **Chemical Bonding**: Atoms bond by sharing or transferring electrons, forming covalent or ionic bonds. For example, water (H2O) is formed by covalent bonds between hydrogen and oxygen.
### Intermolecular Forces
Intermolecular forces are the forces that act between molecules. Examples include hydrogen bonds (e.g., in water) and Van der Waals forces (e.g., in noble gases).
### Absorption and Emission Spectra
Hydrogen atom absorbs energy to excite electrons to higher levels, and when they return to ground state, they emit light of specific wavelengths, forming a spectrum.
### Wave-Particle Duality
Electrons exhibit both wave-like and particle-like properties, demonstrated through phenomena such as diffraction and interference, as well as through their quantized energy states.
### Electric and Magnetic Fields of Light
Light consists of electric (E) and magnetic (B) fields oscillating perpendicular to each other and the direction of propagation. Frequency and wavelength are related, as frequency increases with decreasing wavelength.
Feel free to ask for detailed explanations on specific items or more assistance!
1. **(e)** none
2. **(d)** Al3P2
3. **(a)** The H-I bond in HI
4. **(a)** 8
5. **(e)** AsF5
6. **(c)** 0
7. **(c)** 2
8. **(a)** Metallic bond
9. **(a)** Electronegativity
10. **(b)** located in the outermost occupied major energy level
11. **(a)** All three species contain 10 electrons
12. **(e)** Sc3+
13. **(d)** Al3P2
14. **(e)** AsF5
15. **(c)** 0
16. **(d)** two equivalent resonance forms
17. **(b)** 3
18. **(c)** 2
19. **(a)** 8
20. **(e)** 3 N-Cl bonds and 9 lone pairs of electrons
21. **(e)** 1 triple bond between C and N, 1 C-H bond and 1 lone pair of electrons on the N atom.
22. **(c)** CH4 and NH4+
23. **(d)** Valence Bond Theory
24. **(c)** SP3
25. **(d)** Bent
26. **(d)** 90°
27. **(e)** NO
### Part II: Type of Bonding
28. RbCl **Ionic**
29. TiCl2 **Polar covalent** (partly ionic)
30. LiI **Ionic**
31. SbCl3 **Polar covalent**
32. Br2 **Purely covalent**
### Part III: Answer with Explanation
For drawing molecular shapes, predicting bond angles, and calculating formal charges, manual work or diagrams will be needed. Here is how to approach a selection of the problems.
### Example for 30a: BCl2 (AX2)
- **Shape**: Linear
- **Bond Angles**: 180°
### Formal Charge Calculation Example for 31:
**a. NO**
- Formal Charge(N) = 5 - (0 + 1/2 * 2) = 4 - 1 = **3**
- Formal Charge(O) = 6 - (4 + 1/2 * 2) = 6 - 5 = **1**
**b. HPO4^2-**
- Formal Charge for H = 1 - 0 = **0**
- Formal Charge for P = 5 - (0 + 1/2 * 8) = 5 - 4 = **1**
- Formal Charge for O = 6 - (6 + 1/2 *(8)) = 6 - 8 = **-2**
### Energy Calculations
For calculations such as those presented in 32, 34, and 36, use the formula:
\[
E = -R_H \left( \frac{1}{n^2_{final}} - \frac{1}{n^2_{initial}} \right)
\]
Where \( R_H = 2.18 \times 10^{-18} \text{ J} \).
### Wavelength Calculations
Using the relationship:
\[
\lambda = \frac{hc}{E}
\]
Where:
- \( h = 6.626 \times 10^{-34} \text{ J·s} \)
- \( c = 3.00 \times 10^8 \text{ m/s} \)
### Modern Atomic Theory and Chemical Bonding
- **Modern Atomic Theory**: Atoms consist of a nucleus made of protons and neutrons, surrounded by electrons in specific energy levels.
- **Chemical Bonding**: Atoms bond by sharing or transferring electrons, forming covalent or ionic bonds. For example, water (H2O) is formed by covalent bonds between hydrogen and oxygen.
### Intermolecular Forces
Intermolecular forces are the forces that act between molecules. Examples include hydrogen bonds (e.g., in water) and Van der Waals forces (e.g., in noble gases).
### Absorption and Emission Spectra
Hydrogen atom absorbs energy to excite electrons to higher levels, and when they return to ground state, they emit light of specific wavelengths, forming a spectrum.
### Wave-Particle Duality
Electrons exhibit both wave-like and particle-like properties, demonstrated through phenomena such as diffraction and interference, as well as through their quantized energy states.
### Electric and Magnetic Fields of Light
Light consists of electric (E) and magnetic (B) fields oscillating perpendicular to each other and the direction of propagation. Frequency and wavelength are related, as frequency increases with decreasing wavelength.
Feel free to ask for detailed explanations on specific items or more assistance!