1-Quantitative Properties
All the different properties of matter can be classified in two categories:
qualitative and quantitative properties. When a property includes numbers, it
is a quantitative property, and if it doesn’t, then it is a qualitative
property.
Quantitative Properties: When you can describe something numerically through direct or indirect measurement or calculate the properties of matter, then you are shedding light on the quantitative properties of matter. Below, the example used is water (H2O).
Melting Point: The easiest way to look at a melting point is to think of
water. When you put water in a freezer, it freezes. Why? The air temperature in
the freezer is less than 0 degrees Celsius (water solidification point), so the
water turns into ice. Then, when the ice is taken out and placed in an area
with a temperature at or above +1, it will start to melt; thus proving that the
melting point of water is 0 degrees Celsius. A melting point is the temperature
at which a solid gains enough energy for the molecules to break away from
each other, and morph into a liquid.
Boiling Point: Water starts to boil at 100 degrees Celsius, but can evaporate
at any temperature when it is a liquid. For example, when a substance boils in
a pot, it turns to gas at the bottom, closer to the heat source where it (of
course) hotter. (For a liquid to break away from the other molecules as a gas,
enough heat must be added, just like a solid to a liquid.) Then, those bubbles
burst up rapidly to the top, where the gas goes into the air and spreads out. A
boiling point is the temperature that the above starts to happen.
Freezing/Solidification Point: Using the example of water, when you freeze a glass of water, it turns to ice. However, even though ice is a different name for H2O, ice is just the simple name for solid water. 0 degrees Celsius is the freezing point of water; while the freezing point of silver is 1234.93. The common assumption is that something that is frozen is cold; so if metal is hot to touch on a hot day, is it still frozen? The answer is yes, because something that is frozen is something that is solid. Ink is not a solid at room temperatures, but if you freeze it (reduce the temperature), it will turn solid. A freezing point is the temperature that a liquid changes to a solid.