Question 1:

The correct answer is C.

• Central Part: Nucleus

• Sub-atomic Particles: Protons and neutrons

The nucleus is the dense, positively charged center of an atom, and it contains protons and neutrons (collectively called nucleons). Electrons orbit the nucleus in electron shells and are not found in the nucleus.

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 2:

Neutron
(Neutrons have a mass of about 1 amu and are electrically neutral.)

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 3:

Electron
(Electrons carry a negative charge of -1.)

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 4:

Electron
(Electrons are extremely light, with a mass approximately 1/1836 that of a proton or neutron.)

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 5:

The correct answer is B. protons equals the number of electrons.

Explanation:
Atoms are electrically neutral because they contain equal numbers of protons (positively charged) and electrons (negatively charged). Their charges cancel each other out.

• A is incorrect because the number of protons and neutrons does not affect the overall charge (neutrons have no charge).

• C is incorrect because electrons and neutrons are not equal in count in a neutral atom, and neutrons don't affect charge anyway.

• D is incorrect because the proton/neutron ratio has nothing to do with electrical charge.

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 6:

The correct answer is A. 2, 8, 6.

Explanation:
Electrons are arranged in energy levels (shells) around the nucleus. The maximum number of electrons that can occupy the first four shells is 2, 8, 8, and 18 respectively. Electrons fill the shells in order, starting from the innermost shell.

For an atom with 16 electrons:

• Shell 1 holds a maximum of 2 electrons → remaining: 14

• Shell 2 holds a maximum of 8 electrons → remaining: 6

• Shell 3 holds the remaining 6 electrons (it can hold up to 8, so 6 fits here)

This gives the electronic configuration: 2, 8, 6.

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 7:

• Protons = 9, Electrons = 9 → neutral atom (matches)

• Neutrons = Mass number - Protons = 19 - 9 = 10

Answer for 7: Neutrons = 10

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 8 & 9:

• Neutrons = 20 (given)

• Mass number = Protons + Neutrons

• But we don't have Protons yet. However, for a neutral atom, Protons = Electrons = 17.

• So Protons = 17

• Mass number = 17 + 20 = 37

Answer for 8+9: Protons = 17, Mass number = 37

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 10:

The correct answer is A. W and X.

Explanation:
Isotopes are atoms of the same element that have the same number of protons (and therefore the same atomic number) but different numbers of neutrons.

• W and X both have 19 protons (same element) but differ in neutron numbers (19 vs 20) → isotopes.

• W and Y have different proton numbers (19 vs 20) → different elements.

• Y and Z both have 20 protons (same element), but Y has 19 electrons (it's an ion, not a neutral atom). Isotopes are defined for atoms (neutral), so Y and Z are not considered isotopes of each other because Y is not a neutral atom.

• X and Z have different proton numbers (19 vs 20) → different elements.

Therefore, the only isotopes are W and X.

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.