RockLicker · Grade 6 · Lesson 1 of 5

Crystals from a Solution

Explain how evaporation can lead to crystal growth and distinguish a model from a field identification.

  • Grade 6
  • 50 minutes
  • Worksheet + teacher guidance
Back to Grade 6

What you will learn

Some dissolved materials can form crystals as water is lost and the solution becomes supersaturated. Crystal shape reflects internal order, but a classroom shape alone is not a universal identification test.

Words to use

  • solution: material dissolved in a liquid
  • evaporation: liquid water becoming vapor
  • crystal: solid with ordered internal structure

Evidence for this lesson

Illustrative sequence: Day 0—clear prepared salt solution, no visible crystals. Day 2—lower water level, small crystals at the dish edge. Day 4—still lower level, more visible crystals. Growth timing varies with conditions.

Use the supplied record as written; do not invent missing results.

Work through the activity

  1. 10 min · Read initial conditionsThe salt is dissolved in water and appears clear. Distinguish dissolved salt from visible solid grains floating in a mixture.
  2. 15 min · Track changeUse the three-day observations below. Draw water level and visible solids for each day. For the optional demonstration, schedule a later check rather than expecting crystals within one lesson.
  3. 15 min · Explain mechanismDescribe how water loss can increase the concentration until crystals form. Avoid saying salt evaporated with the water.
  4. 10 min · Evaluate limitsState what you know because the teacher prepared the solution and what you could not infer from an unknown photograph alone.
RockLicker
GRADE 6 · LESSON 1

Crystals from a Solution

Draw on the printed sheet or write, type or dictate your response.
Draw on the printed sheet or write, type or dictate your response.
Draw on the printed sheet or write, type or dictate your response.
Draw on the printed sheet or write, type or dictate your response.

Responses stay in this open page only. Print before closing or changing pages; no student record is stored online.

Check your understanding

As water evaporates from this dish, the salt …

Teacher & family guide · answers and assessment

Grade 6 · Crystals from a Solution

Learning goal: Explain how evaporation can lead to crystal growth and distinguish a model from a field identification.

Expected responses

  1. Table salt in water, according to the supplied preparation.
  2. Water level fell; visible crystals appeared and increased in the illustrative sequence.
  3. Loss of water concentrates dissolved salt; sufficient supersaturation allows crystal growth.
  4. No. Composition and additional properties/context are needed.

Understanding check: can remain and form crystals. The demonstration removes water while salt remains; crystals can form as conditions allow.

Watch for this misconception

Evaporation removes water; it does not mean the dissolved salt vanished or became a different mineral.

Assess the evidence

Look for the observations, calculation or explanation named in the learning goal. Accept accurate drawings and dictated responses. Use the expected responses to discuss reasoning; a correct guess without explanation is a starting point for another conversation.

Adapt and extend

Read prompts aloud, enlarge print or let a partner record the learner’s explanation. Compare equal dishes kept under different safe room conditions, with a teacher-approved multi-day plan.