Question 1:

The centre of an atom is the nucleus, which contains:

• Protons (positive charge)

• Neutrons (no charge)

Electrons orbit the nucleus, so they are not in the centre.

Correct answer: C. neutrons and protons

*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:

The centre part of an atom is called the nucleus (not "nucleole").
What orbits around the nucleus are electrons.

That matches option C.

*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:

Let’s match each description to the correct particle:

3. Has a negative charge.
→ Electron

4. Has a mass of 1 atomic unit and a positive charge.
→ Proton
(Neutron also has ~1 atomic unit mass but is neutral; electron mass is ~1/1836 u)

5. Has a neutral charge.
→ 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 4:

Let’s match each description to the correct particle:

3. Has a negative charge.
→ Electron

4. Has a mass of 1 atomic unit and a positive charge.
→ Proton
(Neutron also has ~1 atomic unit mass but is neutral; electron mass is ~1/1836 u)

5. Has a neutral charge.
→ 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:

Let’s match each description to the correct particle:

3. Has a negative charge.
→ Electron

4. Has a mass of 1 atomic unit and a positive charge.
→ Proton
(Neutron also has ~1 atomic unit mass but is neutral; electron mass is ~1/1836 u)

5. Has a neutral charge.
→ 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 6:

The symbol is written as:

• The top number (9) is the mass number = number of protons + neutrons.

• The bottom number (4) is the atomic number = number of protons.

Top number: mass number = total number of nucleons in the nucleus.

Looking at the options:
A. Number of protons → no, that’s the bottom number.
B. Number of protons plus electrons → no, electrons are not in the nucleus and not counted in mass number.
C. Number of neutrons → no, that would be 5, not 9.
D. Mass of the nucleus → yes, in atomic mass units (approximately). More accurately it's the nucleon count, which represents the nucleus mass relative to 1/12 of carbon-12.

Among these, D is the intended correct choice in this context.

*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:

• The bottom number (4) is the atomic number.

• The atomic number = number of protons in the nucleus.

Looking at the options:

A. The number of protons. ✅ Correct
B. The number of protons plus electrons ❌ (electrons aren’t in the nucleus, and in a neutral atom, protons = electrons, but that’s not what the bottom number means)
C. The number of neutrons ❌ (neutrons = mass number − atomic number = 9 − 4 = 5)
D. The mass of the nucleus ❌ (that’s roughly the mass number, 9)

*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:

The symbol is written as:

• Bottom number (38) = atomic number = number of protons

• Top number (90) = mass number = protons + neutrons

Neutrons = mass number − protons = 90 − 38 = 52

So:
Protons = 38
Neutrons = 52

That matches option D.

*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 9:

The definition of isotopes:

• Same atomic number (same number of protons)

• Different mass number (different number of neutrons)

Checking the options:

A. same number of protons but a different number of neutrons ✅ Correct
B. different number of protons ❌ (that would be different elements, not isotopes)
C. same number of protons but different number of electrons ❌ (that would be ions, not isotopes)
D. different number of protons ❌ (again, different elements)

*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:

From the previous question:
Strontium-90 has 38 protons and 52 neutrons.

A different isotope of strontium must:

• Have the same number of protons (38)

• Have a different number of neutrons

Check each option:

A. 90 p, 91 n → Wrong number of protons (90, not 38)
B. 39 p, 52 n → Wrong number of protons (39, not 38)
C. 38 p, 53 n ✅ Same protons (38), different neutrons (53) → different isotope of strontium
D. 53 p, 38 n → Wrong number of protons (53, not 38)

*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.