Physical Properties
Science: KS3, topic 2.4.1
Physical Properties of Elements
Physical properties of elements are properties of elements that we are able to test without them undergoing any changes.
Physical properties
- These properties are seen and tested without changing the element.
- We will look at the different properties on the next slides...
Colour
- Colours of the elements vary.
- Most metals are silver in colour.
- Gases like hydrogen and helium are colourless.
- Carbon is black.
- Sulphur is yellow.
Density
- The density of an element will determine if it will sink or float.
- Hydrogen has the lowest density of all elements.
- Helium has the second lowest. This is why hydrogen and helium float in air.
- Lithium is the least dense metal which is why it floats on water.
- Mercury is the only metal that is liquid at room temperature, and it is also 13.5x more dense than water.
- This means other metals could float on mercury but sink in water.
Boiling point
- The boiling point is the temperature that an element will change from a liquid to a gas.
- It is also the temperature of condensation – when an element will change from a gas to a liquid.
- The boiling point of water is 100°C. But water is a compound, not an element.
- The element with the lowest boiling point is helium at -269°C.
- The element with the highest boiling point is rhenium at 5,596°C, followed by tungsten at 5,555°C.
Melting point
- The melting point is the temperature at which an element will change from a solid to a liquid. It is also the temperature of freezing - when an element will change from a liquid to a solid.
- The melting point of water is 0°C. But water is a compound, not an element.
- The element with the lowest melting point is helium at -272°C.
- The element with the highest melting point is carbon at 4,500°C.
Test yourself on Physical Properties
What colour are most metals?
Which of these are true of boiling and melting points?
Water boils at 100°C. Which element has a boiling point closest to 100°C?