Lecture 1 – Matter & Its State

ACKNOWLEDGEMENT:

Figure	Source of Figure
Figure 1	chemstuff.co.uk
Figure 2	chemstuff.co.uk
Figure 3	www.mit.edu
Figure 4	sciencelanguagegallery.wikispaces.com

Matter:

Matter is anything that has mass and occupies space. Matter exists in either one of the three states: Solid, Liquid or Gas.

Matter is made up of many small particles. These particles are held together by inter-particular forces of attraction. The strength of these forces, govern the state of matter.

Solids:

Figure 1:

In solids, the particles are held together by very very strong forces of attraction. They are packed together and cannot move. The particles can only vibrate about their fixed positions. This arrangement gives the solid, its fixed shape and fixed volume.

Liquids:

Figure 2:

In liquids, the particles are clumped together in variable clumps of different sizes. These clumps of particles are free to move within the body/volume of the liquid. The forces of attraction are strong to keep the particles together but not strong enough to bind them together. Thus, liquids have a fixed volume but no fixed shape and can take the shape of the container they are poured in.

Gases:

Figure 3:

In gases, the particles are far apart. They have very weak inter-particular forces of attraction thus can freely move. Thus, gases have no fixed volume and no fixed shape.

Table 1: Properties of the different states of matter and their comparison

	Solid	Liquid	Gas
Shape	Definite shape	Take shape of the container	Diffuse and spread into all the space provided to it
Volume	Fixed volume	Fixed volume	No fixed volume
Movement of particles	Particles vibrate about their fixed positions	Particles can move freely within the volume of the liquid	Particles diffuse and move freely in all the space available to them
Arrangement of Particles	Particles are packed together	Particles are close, but not tightly held and can move	Particles further away from one another
Compressibility	Not compressible	Slightly compressible	Easily compressible
Inter-particular forces of attraction	Very strong forces of attraction between particles	Strong forces of attraction between particles	Very weak forces of attraction between particles

Note: The states of matter are interchangeable from solid to liquids and liquids to gas and vice versa, by the application or removal of heat, respectively.

Figure 4:

Sublimation: Sublimation is a process in which a solid directly changes to a gas without going through the liquid phase.