This question tests your understanding of atomic structure—how protons, neutrons, and electrons are arranged in atoms and ions, and how atomic number and mass number relate to these subatomic particles. Every atom consists of three types of subatomic particles: protons (positive charge, in the nucleus, number equals atomic number Z and defines which element it is—all oxygen atoms have exactly 8 protons), neutrons (neutral/no charge, also in nucleus, number equals mass number A minus atomic number Z, so neutrons = A - Z), and electrons (negative charge, in electron cloud around nucleus, equal to protons in neutral atoms for charge balance). For ions, electrons change while protons stay the same: positive ions (cations) have fewer electrons than protons because they've lost electrons, and negative ions (anions) have more electrons than protons because they've gained electrons. The key formulas: protons = atomic number, neutrons = mass number - atomic number, electrons = protons for neutral atoms or protons - charge for ions! For oxygen-16, the atomic number Z is 8, so protons = 8; mass number A is 16, so neutrons = 16 - 8 = 8; and since it's neutral, electrons = 8. Choice B correctly determines the number of protons, neutrons, and electrons by properly using atomic number, mass number, and charge relationships. A common distractor like Choice A might mistakenly use the mass number as neutrons without subtracting, but remember neutrons = A - Z, not A alone—keep practicing to avoid that! The particle counting recipe: (1) PROTONS: Always equal atomic number (look it up or given). This never changes—element identity depends on proton count. (2) NEUTRONS: Subtract atomic number from mass number (A - Z). For oxygen-16: mass 16, atomic number 8, so 16 - 8 = 8 neutrons. (3) ELECTRONS: For neutral atoms, electrons = protons. For ions, electrons = protons - charge (if charge is +2, subtract 2 electrons; if charge is -1, add 1 electron—the negative sign in subtraction handles this!). Quick checks to verify your answer: (1) Proton count should match atomic number exactly. (2) For neutral atoms, protons should equal electrons. (3) For ions, the charge should equal protons minus electrons. (4) Mass number should equal protons plus neutrons (check: 8 + 8 = 16 for oxygen-16, correct!). These verification steps catch most errors before you finalize your answer!

This question tests your understanding of atomic structure—how protons, neutrons, and electrons are arranged in atoms and ions, and how atomic number and mass number relate to these subatomic particles. Every atom consists of three types of subatomic particles: protons (positive charge, in the nucleus, number equals atomic number Z and defines which element it is—all sodium atoms have exactly 11 protons), neutrons (neutral/no charge, also in nucleus, number equals mass number A minus atomic number Z, so neutrons = A - Z), and electrons (negative charge, in electron cloud around nucleus, equal to protons in neutral atoms for charge balance). For ions, electrons change while protons stay the same: positive ions (cations) have fewer electrons than protons because they've lost electrons (Na⁺ has 11 protons but 10 electrons, having lost 1), and negative ions (anions) have more electrons than protons because they've gained electrons. The key formulas: protons = atomic number, neutrons = mass number - atomic number, electrons = protons for neutral atoms or protons - charge for ions! For ^{23}Na^+, the atomic number Z is 11, so protons = 11; mass number A is 23, so neutrons = 23 - 11 = 12; and with +1 charge, electrons = 11 - (+1) = 10. Choice C correctly determines the number of protons, neutrons, and electrons by properly using atomic number, mass number, and charge relationships. A distractor like Choice A might forget to adjust electrons for the ion's charge, but remember for positive ions, subtract the charge value from protons to get electrons—you've got this! The particle counting recipe: (1) PROTONS: Always equal atomic number (look it up or given). This never changes—element identity depends on proton count. (2) NEUTRONS: Subtract atomic number from mass number (A - Z). For sodium-23: mass 23, atomic number 11, so 23 - 11 = 12 neutrons. (3) ELECTRONS: For neutral atoms, electrons = protons. For ions, electrons = protons - charge (if charge is +2, subtract 2 electrons; if charge is -1, add 1 electron—the negative sign in subtraction handles this!). Quick checks to verify your answer: (1) Proton count should match atomic number exactly. (2) For neutral atoms, protons should equal electrons. (3) For ions, the charge should equal protons minus electrons (check: 11 - 10 = +1 for Na⁺, correct!). (4) Mass number should equal protons plus neutrons (check: 11 + 12 = 23, correct!). These verification steps catch most errors before you finalize your answer!

This question tests your understanding of atomic structure—how protons, neutrons, and electrons are arranged in atoms and ions, and how atomic number and mass number relate to these subatomic particles, especially calculating charge. Every atom consists of three types of subatomic particles: protons (positive charge, in the nucleus, number equals atomic number Z and defines which element it is—all sulfur atoms have exactly 16 protons), neutrons (neutral/no charge, also in nucleus, number equals mass number A minus atomic number Z, so neutrons = A - Z), and electrons (negative charge, in electron cloud around nucleus, equal to protons in neutral atoms for charge balance). For ions, electrons change while protons stay the same: positive ions (cations) have fewer electrons than protons because they've lost electrons, and negative ions (anions) have more electrons than protons because they've gained electrons. The key formulas: protons = atomic number, neutrons = mass number - atomic number, electrons = protons for neutral atoms or protons - charge for ions! With 16 protons and 18 electrons, charge = protons - electrons = 16 - 18 = -2 (or 2- since more electrons make it negative). Choice A correctly determines the ion’s charge by comparing protons and electrons accurately. A distractor like Choice B might reverse the sign, but remember charge = protons - electrons, so more electrons mean negative—keep that in mind! The particle counting recipe: (1) PROTONS: Always equal atomic number (look it up or given). This never changes—element identity depends on proton count. (2) NEUTRONS: Subtract atomic number from mass number (A - Z). (3) ELECTRONS: For neutral atoms, electrons = protons. For ions, electrons = protons - charge (if charge is +2, subtract 2 electrons; if charge is -1, add 1 electron—the negative sign in subtraction handles this!). Quick checks to verify your answer: (1) Proton count should match atomic number exactly. (2) For neutral atoms, protons should equal electrons. (3) For ions, the charge should equal protons minus electrons (check: 16 - 18 = -2, correct!). (4) Mass number should equal protons plus neutrons (check: 16 + 16 = 32, though not given, it's consistent!). These verification steps catch most errors before you finalize your answer!

This question tests your understanding of atomic structure—how protons, neutrons, and electrons are arranged in atoms and ions, and how atomic number and mass number relate to these subatomic particles. Every atom consists of three types of subatomic particles: protons (positive charge, in the nucleus, number equals atomic number Z and defines which element it is—all magnesium atoms have exactly 12 protons), neutrons (neutral/no charge, also in nucleus, number equals mass number A minus atomic number Z, so neutrons = A - Z), and electrons (negative charge, in electron cloud around nucleus, equal to protons in neutral atoms for charge balance). For ions, electrons change while protons stay the same: positive ions (cations) have fewer electrons than protons because they've lost electrons (Mg²⁺ has 12 protons but 10 electrons, having lost 2), and negative ions (anions) have more electrons than protons because they've gained electrons. The key formulas: protons = atomic number, neutrons = mass number - atomic number, electrons = protons for neutral atoms or protons - charge for ions! For ^${24}Mg^{2+}$, Z=12 so protons=12; A=24 so neutrons=24-12=12; charge +2 so electrons=12 - (+2)=10. Choice A correctly determines the number of protons, neutrons, and electrons by properly using atomic number, mass number, and charge relationships. A distractor like Choice D might add instead of subtract for electrons, but for positive ions, subtract the charge from protons to find electrons—keep practicing, you're improving! The particle counting recipe: (1) PROTONS: Always equal atomic number (look it up or given). This never changes—element identity depends on proton count. (2) NEUTRONS: Subtract atomic number from mass number (A - Z). For magnesium-24: mass 24, atomic number 12, so 24 - 12 = 12 neutrons. (3) ELECTRONS: For neutral atoms, electrons = protons. For ions, electrons = protons - charge (if charge is +2, subtract 2 electrons; if charge is -1, add 1 electron—the negative sign in subtraction handles this!). Quick checks to verify your answer: (1) Proton count should match atomic number exactly. (2) For neutral atoms, protons should equal electrons. (3) For ions, the charge should equal protons minus electrons (check: 12 - 10 = +2 for Mg²⁺, correct!). (4) Mass number should equal protons plus neutrons (check: 12 + 12 = 24, correct!). These verification steps catch most errors before you finalize your answer!

This question tests your understanding of atomic structure—how protons, neutrons, and electrons are arranged in atoms and ions, and how atomic number and mass number relate to these subatomic particles, specifically for isotopes. Every atom consists of three types of subatomic particles: protons (positive charge, in the nucleus, number equals atomic number Z and defines which element it is—all carbon atoms have exactly 6 protons), neutrons (neutral/no charge, also in nucleus, number equals mass number A minus atomic number Z, so neutrons = A - Z), and electrons (negative charge, in electron cloud around nucleus, equal to protons in neutral atoms for charge balance). Isotopes are atoms of the same element (same Z, same protons) but with different mass numbers (different neutrons), like carbon-12 with 6 neutrons and carbon-14 with 8 neutrons. The key formulas: protons = atomic number, neutrons = mass number - atomic number, electrons = protons for neutral atoms or protons - charge for ions! For carbon-12 and carbon-14, both have Z=6 so 6 protons, but neutrons differ: 12-6=6 vs 14-6=8, making them isotopes with same protons but different neutrons. Choice B correctly compares them by recognizing isotopes share proton count but vary in neutrons. A distractor like Choice A reverses protons and neutrons, but remember protons define the element and stay the same for isotopes—great job spotting that! The particle counting recipe: (1) PROTONS: Always equal atomic number (look it up or given). This never changes—element identity depends on proton count. (2) NEUTRONS: Subtract atomic number from mass number (A - Z). For carbon-12: 12 - 6 = 6 neutrons; for carbon-14: 14 - 6 = 8. (3) ELECTRONS: For neutral atoms, electrons = protons. Quick checks to verify your answer: (1) Proton count should match atomic number exactly. (2) For isotopes, check same Z but different A. (3) Mass number should equal protons plus neutrons (check: 6 + 6 = 12, correct!). These verification steps catch most errors before you finalize your answer!

This question tests your understanding of atomic structure—how protons, neutrons, and electrons are arranged in atoms and ions, and how atomic number and mass number relate to these subatomic particles. Every atom consists of three types of subatomic particles: protons (positive charge, in the nucleus, number equals atomic number Z and defines which element it is—all chlorine atoms have exactly 17 protons), neutrons (neutral/no charge, also in nucleus, number equals mass number A minus atomic number Z, so neutrons = A - Z), and electrons (negative charge, in electron cloud around nucleus, equal to protons in neutral atoms for charge balance). For ions, electrons change while protons stay the same: positive ions (cations) have fewer electrons than protons because they've lost electrons, and negative ions (anions) have more electrons than protons because they've gained electrons (Cl⁻ has 17 protons but 18 electrons, having gained 1). The key formulas: protons = atomic number, neutrons = mass number - atomic number, electrons = protons for neutral atoms or protons - charge for ions! For ^{35}Cl^-, the atomic number Z is 17, so protons = 17; with -1 charge, electrons = 17 - (-1) = 18 (adding 1 for the negative charge). Choice B correctly determines the number of electrons by properly using atomic number and charge relationships. A distractor like Choice A might forget to add an electron for the negative ion, but remember for anions, electrons = protons + |charge|—keep building that intuition! The particle counting recipe: (1) PROTONS: Always equal atomic number (look it up or given). This never changes—element identity depends on proton count. (2) NEUTRONS: Subtract atomic number from mass number (A - Z). (3) ELECTRONS: For neutral atoms, electrons = protons. For ions, electrons = protons - charge (if charge is +2, subtract 2 electrons; if charge is -1, add 1 electron—the negative sign in subtraction handles this!). Quick checks to verify your answer: (1) Proton count should match atomic number exactly. (2) For neutral atoms, protons should equal electrons. (3) For ions, the charge should equal protons minus electrons (check: 17 - 18 = -1 for Cl⁻, correct!). (4) Mass number should equal protons plus neutrons. These verification steps catch most errors before you finalize your answer!

This question tests your understanding of atomic structure—how protons, neutrons, and electrons are arranged in atoms and ions, and how atomic number and mass number relate to these subatomic particles. Every atom consists of three types of subatomic particles: protons (positive charge, in the nucleus, number equals atomic number Z and defines which element it is), neutrons (neutral/no charge, also in nucleus, number equals mass number A minus atomic number Z, so neutrons = A - Z), and electrons (negative charge, in electron cloud around nucleus, equal to protons in neutral atoms for charge balance). For ions, electrons change while protons stay the same: positive ions (cations) have fewer electrons than protons because they've lost electrons, and negative ions (anions) have more electrons than protons because they've gained electrons. The key formulas: protons = atomic number, neutrons = mass number - atomic number, electrons = protons for neutral atoms or protons - charge for ions! With 9 protons, the element is fluorine (Z=9); mass number A=19, so neutrons=19-9=10. Choice B correctly identifies the element as fluorine with 10 neutrons by using atomic number and mass number properly. A distractor like Choice A might miscount neutrons or confuse elements, but remember Z=8 is oxygen, and neutrons=A-Z=19-9=10 for Z=9—nice work! The particle counting recipe: (1) PROTONS: Always equal atomic number (look it up or given). This never changes—element identity depends on proton count. (2) NEUTRONS: Subtract atomic number from mass number (A - Z). For this atom: mass 19, atomic number 9, so 19 - 9 = 10 neutrons. (3) ELECTRONS: For neutral atoms, electrons = protons. For ions, electrons = protons - charge (if charge is +2, subtract 2 electrons; if charge is -1, add 1 electron—the negative sign in subtraction handles this!). Quick checks to verify your answer: (1) Proton count should match atomic number exactly. (2) For neutral atoms, protons should equal electrons. (3) For ions, the charge should equal protons minus electrons. (4) Mass number should equal protons plus neutrons (check: 9 + 10 = 19, correct!). These verification steps catch most errors before you finalize your answer!

This question tests your understanding of atomic structure—how protons, neutrons, and electrons are arranged in atoms and ions, and how atomic number and mass number relate to these subatomic particles. Every atom consists of three types of subatomic particles: protons (positive charge, in the nucleus, number equals atomic number Z and defines which element it is—all magnesium atoms have exactly 12 protons), neutrons (neutral/no charge, also in nucleus, number equals mass number A minus atomic number Z, so neutrons = A - Z), and electrons (negative charge, in electron cloud around nucleus, equal to protons in neutral atoms for charge balance). For ions, electrons change while protons stay the same: positive ions (cations) have fewer electrons than protons because they've lost electrons, and negative ions (anions) have more electrons than protons because they've gained electrons. The key formulas: protons = atomic number, neutrons = mass number - atomic number, electrons = protons for neutral atoms or protons - charge for ions! Given Z=12 and A=24 for a neutral atom, protons = 12; neutrons = 24 - 12 = 12; electrons = 12. Choice A correctly determines the number of protons, neutrons, and electrons by properly using atomic number, mass number, and charge relationships. A distractor like Choice B might double the neutrons incorrectly, but always calculate neutrons as A - Z— you're doing great! The particle counting recipe: (1) PROTONS: Always equal atomic number (look it up or given). This never changes—element identity depends on proton count. (2) NEUTRONS: Subtract atomic number from mass number (A - Z). For this atom: mass 24, atomic number 12, so 24 - 12 = 12 neutrons. (3) ELECTRONS: For neutral atoms, electrons = protons. For ions, electrons = protons - charge (if charge is +2, subtract 2 electrons; if charge is -1, add 1 electron—the negative sign in subtraction handles this!). Quick checks to verify your answer: (1) Proton count should match atomic number exactly. (2) For neutral atoms, protons should equal electrons. (3) For ions, the charge should equal protons minus electrons. (4) Mass number should equal protons plus neutrons (check: 12 + 12 = 24, correct!). These verification steps catch most errors before you finalize your answer!

This question tests your understanding of atomic structure—how protons, neutrons, and electrons are arranged in atoms and ions, and how atomic number and mass number relate to these subatomic particles. Every atom consists of three types of subatomic particles: protons (positive charge, in the nucleus, number equals atomic number Z and defines which element it is—all nitrogen atoms have exactly 7 protons), neutrons (neutral/no charge, also in nucleus, number equals mass number A minus atomic number Z, so neutrons = A - Z), and electrons (negative charge, in electron cloud around nucleus, equal to protons in neutral atoms for charge balance). For ions, electrons change while protons stay the same: positive ions (cations) have fewer electrons than protons because they've lost electrons, and negative ions (anions) have more electrons than protons because they've gained electrons. The key formulas: protons = atomic number, neutrons = mass number - atomic number, electrons = protons for neutral atoms or protons - charge for ions! For ^{14}N, Z=7, A=14, so neutrons=14-7=7. Choice A correctly determines the number of neutrons by subtracting atomic number from mass number. A distractor like Choice B might confuse mass number with neutrons, but neutrons = A - Z, not A— you're on the right track! The particle counting recipe: (1) PROTONS: Always equal atomic number (look it up or given). This never changes—element identity depends on proton count. (2) NEUTRONS: Subtract atomic number from mass number (A - Z). For nitrogen-14: mass 14, atomic number 7, so 14 - 7 = 7 neutrons. (3) ELECTRONS: For neutral atoms, electrons = protons. For ions, electrons = protons - charge (if charge is +2, subtract 2 electrons; if charge is -1, add 1 electron—the negative sign in subtraction handles this!). Quick checks to verify your answer: (1) Proton count should match atomic number exactly. (2) For neutral atoms, protons should equal electrons. (3) For ions, the charge should equal protons minus electrons. (4) Mass number should equal protons plus neutrons (check: 7 + 7 = 14, correct!). These verification steps catch most errors before you finalize your answer!

This question tests your understanding of atomic structure—how protons, neutrons, and electrons are arranged in atoms and ions, and how atomic number and mass number relate to these subatomic particles. Every atom consists of three types of subatomic particles: protons (positive charge, in the nucleus, number equals atomic number Z and defines which element it is—all calcium atoms have exactly 20 protons), neutrons (neutral/no charge, also in nucleus, number equals mass number A minus atomic number Z, so neutrons = A - Z), and electrons (negative charge, in electron cloud around nucleus, equal to protons in neutral atoms for charge balance). For ions, electrons change while protons stay the same: positive ions (cations) have fewer electrons than protons because they've lost electrons (Ca²⁺ has 20 protons but 18 electrons, having lost 2), and negative ions (anions) have more electrons than protons because they've gained electrons. The key formulas: protons = atomic number, neutrons = mass number - atomic number, electrons = protons for neutral atoms or protons - charge for ions! For ^${40}Ca^{2+}$, Z=20, charge +2, so electrons=20 - (+2)=18. Choice C correctly determines the number of electrons by properly using atomic number and charge. A distractor like Choice A might forget to subtract for the positive charge, but for cations, electrons = protons - charge—great effort! The particle counting recipe: (1) PROTONS: Always equal atomic number (look it up or given). This never changes—element identity depends on proton count. (2) NEUTRONS: Subtract atomic number from mass number (A - Z). (3) ELECTRONS: For neutral atoms, electrons = protons. For ions, electrons = protons - charge (if charge is +2, subtract 2 electrons; if charge is -1, add 1 electron—the negative sign in subtraction handles this!). Quick checks to verify your answer: (1) Proton count should match atomic number exactly. (2) For neutral atoms, protons should equal electrons. (3) For ions, the charge should equal protons minus electrons (check: 20 - 18 = +2 for Ca²⁺, correct!). (4) Mass number should equal protons plus neutrons. These verification steps catch most errors before you finalize your answer!