Chemical Changes: Evidence & Conservation — Drills · Grade 6 Science
Chapter: Matter, Mixtures & Water PropertiesWhat these drills covers
By the end of Chemical Changes: Evidence & Conservation you should be able to:
- I can decide whether a change is chemical by comparing properties before and after.
- I can explain why bubbles or a colour change are not proof on their own.
- I can account for mass that appears to be gained or lost during a reaction.
4 questions, multiple choice and written answer, each with a worked explanation.
Vocabulary used: chemical change, conservation of mass, evidence, system boundary, uncertainty.
Problem 1
- A sample with missing measurements has proved those values are zero.
- Any bubbles or color change conclusively prove a chemical reaction.
- A mass change inside an open container means matter was destroyed.
- chemical change: A change that forms substances with different chemical identities.
Answer and explanation
chemical change: A change that forms substances with different chemical identities.
A change that forms substances with different chemical identities.
Problem 2
- conservation of mass: Matter remains accounted for when the complete relevant system and exchanges are included.
- A mass change inside an open container means matter was destroyed.
- Any bubbles or color change conclusively prove a chemical reaction.
- Repeating any method makes every causal claim true.
Answer and explanation
conservation of mass: Matter remains accounted for when the complete relevant system and exchanges are included.
Matter remains accounted for when the complete relevant system and exchanges are included.
Problem 3
Answer and explanation
No. It crossed the chosen boundary as gas. The mass inside differs from the mass of the complete accounted system.
Compare the scientific meaning and reasoning after an independent attempt. A different accurate supported response can be correct; human review is required.
Problem 4
Answer and explanation
The conclusion depends on the record’s stated method and boundaries; illustrative data are not proof that a real procedure was performed.
Compare the scientific meaning and reasoning after an independent attempt. A different accurate supported response can be correct; human review is required.