Educational worksheet on acids, alkalis, and salts with a pH scale and related questions.

It looks like you've uploaded an image of a crossword puzzle titled "Acids, alkalis and salts". The puzzle includes clues for both across and down entries, all related to chemistry topics involving acids, bases (alkalis), and salts.

Since I can't view or analyze images directly, I’ll need you to provide the text version of the clues (both Across and Down) and any visible words or structure from the grid if possible. Then I can help you solve it step by step and explain the answers.

Alternatively, if you can describe what’s in the image — for example:

- List of Across clues
- List of Down clues
- Any visible words in the grid

— I can proceed with solving it.

For now, here’s how we’d typically approach such a puzzle:

Steps to Solve:

1. Identify key terms: Acids (e.g., HCl, H₂SO₄), Alkalis (e.g., NaOH, KOH), Salts (e.g., NaCl), pH, neutralization, indicators (litmus, phenolphthalein), etc.
2. Use definitions to match clues to chemical terms.
3. Fill in the grid using intersecting letters to confirm answers.

Example Clues & Answers (common ones):

- Across 1: "A substance that turns litmus paper red" → Acid
- Down 5: "A base that dissolves in water" → Alkali
- Across 8: "Reaction between acid and base" → Neutralization
- Down 3: "Salt formed from HCl and NaOH" → Sodium chloride

Please provide the actual clues, and I’ll solve the full puzzle for you!