Unique Properties of Substances Unique Properties Characteristic Properties

Unique Properties of Substances

Unique Properties • Characteristic Properties are properties unique to a particular substance • Characteristic properties are always the same for a substance even if that substance changes shape or quantity. • Examples: – Melting point - Boiling point – Freezing point - Density Question: Explain why the boiling point of water is a characteristic physical property, but the temperature and the volume of a glass of water are not.

How are you identified? • • • Hair colour Eye colour Skin colour Fingerprints DNA • These characteristics can be used to identify you • Which ones are unique to you?

Characteristic Properties • Just like your finger prints and DNA, substances have properties that are unique to them • Characteristic Properties are properties unique to a particular substance

Characteristic Properties • These properties help scientists positively identify a substance • Characteristic properties are always the same for a substance even if that substance changes shape or quantity.

Examples of Characteristic Properties • • Melting point Boiling point Freezing point density

Can you Identify Me? • • • I have a density of 1 g/cm 3 I have a clear colour I am not flammable I am liquid at room temperature I have a boiling point of 100°C What am I ? ? ?

I'm Water!

Lets Try Again!! • • • I have a density of 8. 93 g/cm 3 I have a red colour I react to oxygen and turn green I am a solid at room temperature I have a boiling point of 2, 562°C What am I ? ? ?

I’m Copper!!

Questions… Explain why the boiling point of water is a characteristic physical property, but the temperature and the volume of a glass of water are not.