Properties and Changes

Matter can be described and identified by physical and chemical properties. Physical _________chemicalspropertiessubstancestextures have to do with appearance. You can observe many physical properties with your senses and by measuring the length, _________widthdensityheightproperty, height, mass and density of a substance. _________ChemicalMatterDescribedPhysical properties include color, shape, smell, texture, taste and size. The state of matter (whether it's a solid, _________watermoleculeliquidatom, or gas) and the _________timetemperaturedesigncylinder at which the substance boils, melts or freezes are also physical properties. Magnetic properties are physical properties as well.

_________ChemicalPhysicalSubstanceGaseous properties, on the other hand, have more to do with the atomic or molecular composition of matter. Chemical properties deal with how substances react with other _________propertiesphysicalsdegreessubstances such as water, air or fire.

A physical change has occurred when a substance changes color, size, shape, temperature or state. A _________temperaturephysicalchemicalcolor change has occurred when a substance has changed into something new or _________similardifferentfamiliarorigional so that the original substance is gone. Digestion and combustion are examples of chemical changes. A chemical change takes place in a _________batterybulbchangeswitch to produce electricity when you turn on a flashlight.

Chemical changes are sometimes represented by a chemical formula:

2H₂ + O₂ = 2H₂O

This formula states that two hydrogen gas molecules react with one oxygen gas molecule to produce two molecules of water.