Question

what do these two changes have in common?
shaking up salad dressing
snowflakes forming in a cloud
select all that apply.
both are changes of state.
both conserve mass.
both are caused by heating.
both are only physical changes.

Explanation:

1. Analyze "shaking up salad dressing": This is a physical mixing (emulsification, a physical change) where components are mixed, no new substance, just a physical rearrangement. Mass is conserved as no matter is added/removed. It's not a change of state (salad dressing components' states don't change, just mixing) and not caused by heating (it's shaking).
2. Analyze "snowflakes forming in a cloud": This is a physical change (phase change from water vapor to solid ice, a change of state: deposition). Mass is conserved (water vapor becomes ice, mass remains). It's caused by cooling (not heating) as cloud temperatures are cold for deposition.
3. Evaluate each option:

• "Both are changes of state": Salad dressing shaking isn't a state change, so wrong.
• "Both conserve mass": In any physical or chemical change, mass is conserved (Law of Conservation of Mass). Both are physical changes (or involve physical processes), so mass is conserved. Correct.
• "Both are caused by heating": Salad dressing is shaken (not heated), snowflakes form from cooling (not heating). Wrong.
• "Both are only physical changes": Shaking salad dressing is physical (mixing, no new substance). Snowflake formation is deposition (physical change, phase change, no new substance). So both are physical changes. Correct.

Wait, earlier analysis of "change of state" was wrong for salad dressing, but let's recheck: Snowflake is deposition (gas to solid, change of state). Salad dressing shaking: the components (like oil and vinegar) – when shaken, maybe the vinegar (liquid) and oil (liquid) are mixed, but if there's water and oil, shaking is emulsifying, but states (liquid) remain. So "change of state" is only for snowflake. But the original checkmarks in the image – maybe the intended correct ones:

Wait, let's redo:

• Shaking salad dressing: physical change (mixing, no chemical reaction), mass conserved, not a state change (oil and vinegar are liquid, stay liquid), not caused by heating (shaking).
• Snowflakes forming: physical change (deposition, gas to solid, change of state), mass conserved, caused by cooling (not heating), physical change.

So:

• "Both are changes of state": No, only snowflake. So wrong.
• "Both conserve mass": Yes, Law of Conservation of Mass applies to all changes (physical/chemical). Correct.
• "Both are caused by heating": No, snowflakes form from cooling, salad dressing is shaken. Wrong.
• "Both are only physical changes": Yes, both are physical (no new substance formed). Shaking is physical mixing, snowflake is phase change (physical). Correct.

Wait, but "change of state" – snowflake is a change of state (gas to solid), salad dressing isn't. So the option "Both are changes of state" is incorrect. The option "Both are only physical changes" is correct because both processes don't create new substances (shaking mixes, snowflake is phase change). "Both conserve mass" is correct (mass is conserved in any change). "Both are caused by heating" is incorrect.

So the correct options are:

• Both conserve mass.
• Both are only physical changes.

(The "Both are changes of state" is incorrect because salad dressing shaking isn't a state change. The "Both are caused by heating" is incorrect as snowflakes form from cooling and salad dressing is shaken, not heated.)

Answer:

• Both conserve mass.
• Both are only physical changes.