Sublimation is the direct conversion of a solid to vapours without melting. Example: solid CO₂ (dry ice). Naphthalene balls sublime. Energy comes from within, absorbed from surroundings.
❄️ Deposition
Reverse of sublimation: gas → solid. Example: frost formation.
14.3 Quick Check!
- 1. Temperature change during evaporation? (No, but surrounding cools)
- 2. Does ice sublime? (Yes, slowly in dry conditions)
- 3. Other examples: sublimation – iodine; deposition – snow in clouds.
⚙️ Applications of Sublimation
Solid air fresheners
Scented solid sublimes, spreads vapours.
Sublimation Printing
Ink sublimates into fabric, then deposits – permanent.
📌 Key Notes & 35-Minute Lesson Planner
🧊 Dry ice sublimes
📦 Naphthalene balls sublime
❄️ Frost = deposition
👕 Sublimation printing = sublime + deposit
35-Minute Lesson Structure (Teacher)
0-5 min Hook: Show dry ice “smoke” or naphthalene ball – ask “where does it go?”
5-10 min Direct instruction: Define sublimation & deposition, board work with examples (dry ice, frost).
10-15 min Demonstration/activity: (no AV) pass around naphthalene ball (if safe) or describe sublimation printing process with a printed t-shirt sample.
15-22 min Quick check & discussion: Students pair up – list 2 sublimation, 2 deposition examples. Share.
22-30 min Interactive quiz: Use 5 quiz questions from below (whole class oral or mini-whiteboard).
30-35 min Wrap & exit ticket: “One thing you learned about sublimation” – collect on paper slips.
Differentiation: Provide sentence starters for ELL; extend with ‘why is sublimation printing permanent?’ for advanced.
Quick memorization
🧊 Sublimation: “Solid skips liquid – like dry ice”
❄️ Deposition: “Gas to solid – frosty morning”
🔥 Printing: “Ink sublimes, then deposits”