Question 1:

Let’s review the halogens.

Halogens are the elements in Group 17 of the periodic table (F, Cl, Br, I, At, Ts).
Key properties:

• They are non-metals

• They exist as diatomic molecules in their elemental state (F₂, Cl₂, Br₂, I₂, At₂ in theory)

• They are highly reactive

Given these facts, the correct description is:
A. non-metal elements composed of diatomic molecules

Answer: A ✅

*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:

Let’s think about why Group 7 (the halogens) have similar chemical properties.

Chemical properties are mainly determined by the number of electrons in the outermost shell — also called the valence electrons.

Group 7 elements all have 7 valence electrons, which makes them react in similar ways (e.g., gaining 1 electron to form a -1 ion, or sharing in covalent bonds).

• A: electron shells — this is incorrect, because they have different numbers of shells as you go down the group.

• B: electrons — incorrect, total electrons change with atomic number.

• C: outer shell electrons — correct, same number (7) in the outermost shell.

• D: protons — incorrect, proton number is different for each element.

So the correct answer is C.

Answer: 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:

We know that in Group 7 (halogens), reactivity decreases as you go down the group.
This is because:

• Atoms get larger

• The outer shell electrons are farther from the nucleus

• It becomes harder to attract an extra electron (lower electron affinity)

So from top (most reactive) to bottom (least reactive):
Fluorine > Chlorine > Bromine > Iodine

This matches option A.

Answer: A ✅

*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 + 5:

Let’s look at the pattern for the halogens from fluorine to iodine:

• Fluorine: yellow gas

• Chlorine: green gas

• Bromine: red-brown liquid

• Iodine: grey solid

As we go down the group:

• State changes from gas → liquid → solid (molecular weight and van der Waals forces increase)

• Colour gets darker: yellow → green → red-brown → grey (darkening trend)

Extending to astatine (below iodine):

• State should be solid at room temperature (even more solid than iodine, metallic-looking possibly)

• Colour should be darker than grey, likely black (often described as black or dark metallic)

So predicted: black, solid

Answer: black solid ✅

*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:

• Melting point of iodine = 114°C

• Boiling point must be higher than 114°C

• From the options (85, 100, 180, 300), only 180 and 300 are above 114°C

• Looking at the pattern (boiling points go up by smaller amounts as you go down the group), 180°C is the most reasonable choice

Answer: 180°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 7:

Let's recall the reactivity series for halogens:

Most reactive → Least reactive
Fluorine > Chlorine > Bromine > Iodine

A more reactive halogen can displace a less reactive halogen from its compound.

Check each option:

A. bromine + potassium iodide → potassium bromide and iodine

• Bromine is more reactive than iodine ✅

• Bromine will displace iodine from potassium iodide ✅

• Reaction happens ✅

B. bromine + potassium chloride → potassium bromide and chlorine

• Bromine is less reactive than chlorine ❌

• Bromine cannot displace chlorine ❌

C. iodine + potassium chloride → potassium iodide and chlorine

• Iodine is less reactive than chlorine ❌

• No reaction ❌

D. iodine + potassium bromide → potassium iodide and bromine

• Iodine is less reactive than bromine ❌

• No reaction ❌

✅ Only A will take place.

Answer: A

*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:

Let's think through the reaction:

• Chlorine gas (Cl₂) is bubbled into sodium bromide solution (NaBr).

• Chlorine is more reactive than bromine, so it will displace bromine from sodium bromide.

• The reaction is:

Bromine is produced, which gives the solution a brown/orange color.

This is a displacement reaction (a more reactive element displaces a less reactive one from a compound.

• D. displacement — ✅ correct

Answer: 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 reaction happens because chlorine displaces bromine from sodium bromide.

For displacement to occur, the free halogen (chlorine) must be more reactive than the halogen in the compound (bromine).

That means:
Chlorine is more reactive than bromine ✅

• A says "chlorine is more reactive than sodium bromide" — sodium bromide is a compound, not an element, so this statement is incorrectly phrased (reactivity series compares elements, not compounds) ❌

• B says "chlorine is less reactive than sodium bromide" — wrong ❌

• C says "chlorine is more reactive than bromine" — correct ✅

• D says "chlorine is less reactive than bromine" — wrong ❌

Answer: 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 10:

Let's check each option:

A. Cl + NaBr → NaCl + Br

• Chlorine exists as Cl₂, not Cl (single atoms) ❌

B. Cl₂ + NaBr → NaCl + Br₂

• Not balanced (2 Cl on left, only 1 Cl on right; 1 Br on left, 2 Br on right) ❌

C. Cl₂ + 2NaBr → 2NaCl + Br₂

• Correct formulas ✅

• Balanced ✅

• Correct products ✅

D. Cl₂ + 2NaBr → 2ClBr + 2Na

• Wrong products (ClBr is not formed; sodium metal is not produced) ❌

Answer: 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.