NAS 2 TCC EXAM AND STUDY GUIDE NEWEST 2026
TEST BANK| COMPLETE 300 REAL EXAM QUESTIONS
AND CORRECT VERIFIED ANSWERS/ ALREADY
GRADED A+ (MOST RECENT!!)
1. What is the charge of a neutron?
A) +1
B) -1
C) 0
D) +2
Answer: C) 0
Rationale: Neutrons are neutral subatomic particles found in
the nucleus. Protons carry a +1 charge, electrons carry a -1
charge.
2. Which subatomic particle determines the identity of an
element?
A) Neutron
B) Electron
C) Proton
1
, D) Positron
Answer: C) Proton
Rationale: The atomic number (number of protons) defines
the element. Changing neutrons gives isotopes; changing
electrons gives ions.
3. An atom has 17 protons, 18 neutrons, and 17 electrons.
What is its mass number?
A) 17
B) 34
C) 35
D) 52
Answer: C) 35
Rationale: Mass number = protons + neutrons = 17 + 18 =
35. Electrons have negligible mass.
4. Which isotope has the greatest number of neutrons?
A) C-12
B) C-14
C) O-16
2
, D) O-18
Answer: D) O-18
Rationale: Neutrons = mass number - atomic number. O-18:
18-8=10 neutrons; C-14: 14-6=8; O-16: 16-8=8; C-12:
12-6=6.
5. What is the electron configuration of sodium (Na, atomic
number 11)?
A) 1s²2s²2p⁶3s¹
B) 1s²2s²2p⁵3s²
C) 1s²2s²2p⁶3s²
D) 1s²2s²2p⁶3p¹
Answer: A) 1s²2s²2p⁶3s¹
Rationale: Filling order: 1s, 2s, 2p, 3s. 11 electrons fill up to
3s¹.
6. Which element has the highest electronegativity?
A) Li
B) F
C) O
3
, D) Ne
Answer: B) F
Rationale: Fluorine is the most electronegative element (4.0
on Pauling scale). Neon is a noble gas and does not form
bonds.
7. Moving from left to right across a period, atomic radius
generally _____ due to _____ nuclear charge.
A) increases; decreasing
B) decreases; increasing
C) increases; increasing
D) remains constant; same
Answer: B) decreases; increasing
Rationale: Increased protons pull electrons closer, reducing
atomic radius despite added electrons in the same shell.
8. Which ion is isoelectronic with neon (Ne)?
A) Na⁺
B) Cl⁻
C) Mg²⁻
4
TEST BANK| COMPLETE 300 REAL EXAM QUESTIONS
AND CORRECT VERIFIED ANSWERS/ ALREADY
GRADED A+ (MOST RECENT!!)
1. What is the charge of a neutron?
A) +1
B) -1
C) 0
D) +2
Answer: C) 0
Rationale: Neutrons are neutral subatomic particles found in
the nucleus. Protons carry a +1 charge, electrons carry a -1
charge.
2. Which subatomic particle determines the identity of an
element?
A) Neutron
B) Electron
C) Proton
1
, D) Positron
Answer: C) Proton
Rationale: The atomic number (number of protons) defines
the element. Changing neutrons gives isotopes; changing
electrons gives ions.
3. An atom has 17 protons, 18 neutrons, and 17 electrons.
What is its mass number?
A) 17
B) 34
C) 35
D) 52
Answer: C) 35
Rationale: Mass number = protons + neutrons = 17 + 18 =
35. Electrons have negligible mass.
4. Which isotope has the greatest number of neutrons?
A) C-12
B) C-14
C) O-16
2
, D) O-18
Answer: D) O-18
Rationale: Neutrons = mass number - atomic number. O-18:
18-8=10 neutrons; C-14: 14-6=8; O-16: 16-8=8; C-12:
12-6=6.
5. What is the electron configuration of sodium (Na, atomic
number 11)?
A) 1s²2s²2p⁶3s¹
B) 1s²2s²2p⁵3s²
C) 1s²2s²2p⁶3s²
D) 1s²2s²2p⁶3p¹
Answer: A) 1s²2s²2p⁶3s¹
Rationale: Filling order: 1s, 2s, 2p, 3s. 11 electrons fill up to
3s¹.
6. Which element has the highest electronegativity?
A) Li
B) F
C) O
3
, D) Ne
Answer: B) F
Rationale: Fluorine is the most electronegative element (4.0
on Pauling scale). Neon is a noble gas and does not form
bonds.
7. Moving from left to right across a period, atomic radius
generally _____ due to _____ nuclear charge.
A) increases; decreasing
B) decreases; increasing
C) increases; increasing
D) remains constant; same
Answer: B) decreases; increasing
Rationale: Increased protons pull electrons closer, reducing
atomic radius despite added electrons in the same shell.
8. Which ion is isoelectronic with neon (Ne)?
A) Na⁺
B) Cl⁻
C) Mg²⁻
4
