Physical & Chemical Changes

Demonstration powerpoint

Physical Changes• Physical changes are when the substance is

still the same thing. It has only changed forms.

Size

•Breaking a piece of mossy zinc into pieces.

Shape

•Bending a piece of magnesium strip.

State• Boiling off the water from salt

water. You are left with the salt. Evaporation.

• Dry ice (frozen CO2) goes from a solid to a gas; this is called sublimation.

Chemical Changes•Chemical Changes are

when a new substance is produced that was not there originally.

Color• (unexpected color change)

Clear liquid (ammonia) + clear liquid (PHTH)

Add PHTH to ammonia

= pink (unexpected color change)

Temperature• (unexpected temperature change)

Ammonium nitrate + water

Starting temperature 20⁰ C

Add ammonium nitrate to water

a temperature decrease of 8⁰ C

Bubbles & Fizz

HCl + magnesium strip

= bubbles and fizz

New Substance•(precipitate)

Milk + vinegar =

Swirl it around

Chunky stuff

Steel wool + vinegar = rust

• Another precipitate!