1. classify each description as a physical change or chemical change.\na) milk spoiling in the fridge and…

1. classify each description as a physical change or chemical change.\na) milk spoiling in the fridge and starting to sour\nb) transforming iron into steel using a blast furnace\nc) water evaporating from a sidewalk in a hot day\nd) dissolving sugar into coffee\ne) digesting food after eating a large meal\ne) popping popcorn in a microwave\nf) shredding paper\ng) a firework exploding
Answer
Brief Explanations:
- a) Milk spoiling is a chemical change as new substances are formed by bacterial action.
- b) Transforming iron to steel is a chemical change as the composition changes through reactions in the blast - furnace.
- c) Water evaporating is a physical change as it is a change of state from liquid to gas without changing the substance's chemical identity.
- d) Dissolving sugar in coffee is a physical change as it is a mixture formation without new chemical substances.
- e) Digesting food is a chemical change as enzymes break down food into new substances.
- f) Popping popcorn is a chemical change as heat causes chemical reactions in the kernels.
- g) Shredding paper is a physical change as it only changes the physical form, not the chemical composition.
- h) A firework exploding is a chemical change as it involves rapid chemical reactions producing heat, light, and new substances.
Answer:
a) Chemical change b) Chemical change c) Physical change d) Physical change e) Chemical change f) Chemical change g) Physical change h) Chemical change