WGU C165 INTEGRATED PHYSICAL SCIENCES COMPLETE
EXAM QUESTIONS AND ALL ANSWERS VERIFIED
1. Q: What is the atomic number of an element? ANSWER The atomic number
is the number of protons in the nucleus of an atom, which defines the
element's identity.
2. Q: How many electrons does a neutral atom of carbon (atomic number 6)
have? ANSWER A neutral carbon atom has 6 electrons, equal to its number of
protons.
3. Q: What is an isotope? ANSWER An isotope is a variant of an element with
the same number of protons but a different number of neutrons.
4. Q: Which group of elements are called noble gases? ANSWER Group 18 (VIII)
elements: helium, neon, argon, krypton, xenon, and radon.
5. Q: What is the electron configuration of sodium (Na, atomic number 11)?
ANSWER 1s² 2s² 2p⁶ 3s¹ or [Ne] 3s¹
6. Q: What trend occurs to atomic radius as you move down a group in the
periodic table? ANSWER Atomic radius increases due to additional electron
shells.
7. Q: What is ionization energy? ANSWER The energy required to remove an
electron from a gaseous atom or ion.
8. Q: Which element has the highest electronegativity? ANSWER Fluorine (F)
with an electronegativity of 4.0 on the Pauling scale.
9. Q: What are valence electrons? ANSWER Electrons in the outermost shell of
an atom that participate in chemical bonding.
10. Q: How many valence electrons does chlorine have? ANSWER Chlorine has
7 valence electrons (3s² 3p⁵).
11. Q: What is the maximum number of electrons that can occupy the d
sublevel? ANSWER 10 electrons (5 orbitals × 2 electrons each).
12. Q: Which period does the element calcium belong to? ANSWER Period 4
(electron configuration ends in 4s²).
,13. Q: What is the difference between atomic mass and mass number?
ANSWER Mass number is the sum of protons and neutrons (whole number),
while atomic mass is the weighted average of all isotopes.
14. Q: What type of elements are found in Group 1? ANSWER Alkali metals
(except hydrogen).
15. Q: What is the name for Group 17 elements? ANSWER Halogens (fluorine,
chlorine, bromine, iodine, astatine).
16. Q: How do you determine the number of neutrons in an atom? ANSWER
Subtract the atomic number from the mass number: Neutrons = Mass number
- Atomic number.
17. Q: What is the electron configuration of a chloride ion (Cl⁻)? ANSWER [Ne]
3s² 3p⁶ or [Ar] (gained one electron).
18. Q: Which sublevel is filled before 4s? ANSWER 3p sublevel is filled before
4s.
19. Q: What is the trend for ionization energy across a period? ANSWER
Ionization energy generally increases from left to right across a period.
20. Q: What are the three types of subatomic particles? ANSWER Protons
(positive charge), neutrons (neutral), and electrons (negative charge).
21. Q: Where are protons and neutrons located in an atom? ANSWER In the
nucleus at the center of the atom.
22. Q: What is the charge of an electron? ANSWER -1.602 × 10⁻¹⁹ coulombs (or
simply -1 in atomic units).
23. Q: How many orbitals are in the p sublevel? ANSWER 3 orbitals (px, py, pz).
24. Q: What is the Pauli exclusion principle? ANSWER No two electrons in an
atom can have the same set of four quantum numbers.
25. Q: What is Hund's rule? ANSWER Electrons occupy orbitals singly first, then
pair up, with parallel spins when possible.
Chemical Bonding (26-50)
26. Q: What is an ionic bond? ANSWER An electrostatic attraction between
oppositely charged ions formed by electron transfer.
, 27. Q: What type of bond forms between two nonmetals? ANSWER Covalent
bond (sharing of electrons).
28. Q: What is electronegativity? ANSWER The ability of an atom to attract
shared electrons in a chemical bond.
29. Q: What is a polar covalent bond? ANSWER A covalent bond where
electrons are shared unequally due to differences in electronegativity.
30. Q: What is the molecular geometry of water (H₂O)? ANSWER Bent
(angular) with a bond angle of approximately 104.5°.
31. Q: How many bonding pairs and lone pairs does ammonia (NH₃) have?
ANSWER 3 bonding pairs and 1 lone pair.
32. Q: What is VSEPR theory? ANSWER Valence Shell Electron Pair Repulsion
theory - electron pairs repel each other and arrange to minimize repulsion.
33. Q: What is the molecular geometry of methane (CH₄)? ANSWER
Tetrahedral with bond angles of 109.5°.
34. Q: What type of intermolecular force exists between HF molecules?
ANSWER Hydrogen bonding (strongest type of dipole-dipole interaction).
35. Q: What are London dispersion forces? ANSWER Weak intermolecular
forces caused by temporary dipoles in molecules.
36. Q: Which has stronger intermolecular forces: CH₄ or CH₃OH? ANSWER
CH₃OH due to hydrogen bonding (methane only has London dispersion forces).
37. Q: What is a metallic bond? ANSWER The electrostatic attraction between
metal cations and delocalized electrons (electron sea).
38. Q: How many electrons does carbon need to achieve a stable octet?
ANSWER Carbon needs 4 more electrons (it has 4 valence electrons).
39. Q: What is the Lewis structure rule for the octet rule? ANSWER Atoms tend
to gain, lose, or share electrons to achieve 8 electrons in their valence shell.
40. Q: What is a double bond? ANSWER A covalent bond consisting of two
pairs of shared electrons.
41. Q: What is resonance in chemistry? ANSWER The delocalization of
electrons in molecules that cannot be represented by a single Lewis structure.
EXAM QUESTIONS AND ALL ANSWERS VERIFIED
1. Q: What is the atomic number of an element? ANSWER The atomic number
is the number of protons in the nucleus of an atom, which defines the
element's identity.
2. Q: How many electrons does a neutral atom of carbon (atomic number 6)
have? ANSWER A neutral carbon atom has 6 electrons, equal to its number of
protons.
3. Q: What is an isotope? ANSWER An isotope is a variant of an element with
the same number of protons but a different number of neutrons.
4. Q: Which group of elements are called noble gases? ANSWER Group 18 (VIII)
elements: helium, neon, argon, krypton, xenon, and radon.
5. Q: What is the electron configuration of sodium (Na, atomic number 11)?
ANSWER 1s² 2s² 2p⁶ 3s¹ or [Ne] 3s¹
6. Q: What trend occurs to atomic radius as you move down a group in the
periodic table? ANSWER Atomic radius increases due to additional electron
shells.
7. Q: What is ionization energy? ANSWER The energy required to remove an
electron from a gaseous atom or ion.
8. Q: Which element has the highest electronegativity? ANSWER Fluorine (F)
with an electronegativity of 4.0 on the Pauling scale.
9. Q: What are valence electrons? ANSWER Electrons in the outermost shell of
an atom that participate in chemical bonding.
10. Q: How many valence electrons does chlorine have? ANSWER Chlorine has
7 valence electrons (3s² 3p⁵).
11. Q: What is the maximum number of electrons that can occupy the d
sublevel? ANSWER 10 electrons (5 orbitals × 2 electrons each).
12. Q: Which period does the element calcium belong to? ANSWER Period 4
(electron configuration ends in 4s²).
,13. Q: What is the difference between atomic mass and mass number?
ANSWER Mass number is the sum of protons and neutrons (whole number),
while atomic mass is the weighted average of all isotopes.
14. Q: What type of elements are found in Group 1? ANSWER Alkali metals
(except hydrogen).
15. Q: What is the name for Group 17 elements? ANSWER Halogens (fluorine,
chlorine, bromine, iodine, astatine).
16. Q: How do you determine the number of neutrons in an atom? ANSWER
Subtract the atomic number from the mass number: Neutrons = Mass number
- Atomic number.
17. Q: What is the electron configuration of a chloride ion (Cl⁻)? ANSWER [Ne]
3s² 3p⁶ or [Ar] (gained one electron).
18. Q: Which sublevel is filled before 4s? ANSWER 3p sublevel is filled before
4s.
19. Q: What is the trend for ionization energy across a period? ANSWER
Ionization energy generally increases from left to right across a period.
20. Q: What are the three types of subatomic particles? ANSWER Protons
(positive charge), neutrons (neutral), and electrons (negative charge).
21. Q: Where are protons and neutrons located in an atom? ANSWER In the
nucleus at the center of the atom.
22. Q: What is the charge of an electron? ANSWER -1.602 × 10⁻¹⁹ coulombs (or
simply -1 in atomic units).
23. Q: How many orbitals are in the p sublevel? ANSWER 3 orbitals (px, py, pz).
24. Q: What is the Pauli exclusion principle? ANSWER No two electrons in an
atom can have the same set of four quantum numbers.
25. Q: What is Hund's rule? ANSWER Electrons occupy orbitals singly first, then
pair up, with parallel spins when possible.
Chemical Bonding (26-50)
26. Q: What is an ionic bond? ANSWER An electrostatic attraction between
oppositely charged ions formed by electron transfer.
, 27. Q: What type of bond forms between two nonmetals? ANSWER Covalent
bond (sharing of electrons).
28. Q: What is electronegativity? ANSWER The ability of an atom to attract
shared electrons in a chemical bond.
29. Q: What is a polar covalent bond? ANSWER A covalent bond where
electrons are shared unequally due to differences in electronegativity.
30. Q: What is the molecular geometry of water (H₂O)? ANSWER Bent
(angular) with a bond angle of approximately 104.5°.
31. Q: How many bonding pairs and lone pairs does ammonia (NH₃) have?
ANSWER 3 bonding pairs and 1 lone pair.
32. Q: What is VSEPR theory? ANSWER Valence Shell Electron Pair Repulsion
theory - electron pairs repel each other and arrange to minimize repulsion.
33. Q: What is the molecular geometry of methane (CH₄)? ANSWER
Tetrahedral with bond angles of 109.5°.
34. Q: What type of intermolecular force exists between HF molecules?
ANSWER Hydrogen bonding (strongest type of dipole-dipole interaction).
35. Q: What are London dispersion forces? ANSWER Weak intermolecular
forces caused by temporary dipoles in molecules.
36. Q: Which has stronger intermolecular forces: CH₄ or CH₃OH? ANSWER
CH₃OH due to hydrogen bonding (methane only has London dispersion forces).
37. Q: What is a metallic bond? ANSWER The electrostatic attraction between
metal cations and delocalized electrons (electron sea).
38. Q: How many electrons does carbon need to achieve a stable octet?
ANSWER Carbon needs 4 more electrons (it has 4 valence electrons).
39. Q: What is the Lewis structure rule for the octet rule? ANSWER Atoms tend
to gain, lose, or share electrons to achieve 8 electrons in their valence shell.
40. Q: What is a double bond? ANSWER A covalent bond consisting of two
pairs of shared electrons.
41. Q: What is resonance in chemistry? ANSWER The delocalization of
electrons in molecules that cannot be represented by a single Lewis structure.
