Analysing matter

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Malaysia SPM Form 4 Chemistry, Chapter 1 : Structure of Atom.

Contents 1 Matter 2 Atom, Molecule and Ion 3 Element and Compound 3.1 Element 3.2 Compound 4 The particle theory of matter 4.1 Diffusion 4.1.1 Diffusion in Solid 4.1.2 Diffusion in Liquid 4.1.3 Diffusion in Gas 4.2 Brownian motion 5 Kinetic Theory of Matter

[edit] Matter

Matter is anything that occupies space and has mass.

[edit] Atom, Molecule and Ion

The particles can be atoms, molecules or ions.

Atom	Molecule	Ion
The atom is the smallest, indivisible particle of an element. Atoms of the same element are exactly alike and are different from the atoms of all other elements.	Molecules are the smallest particles of an element or compound that are made up of two or more atoms. Ions are particles that are charged due to loss or gain of electrons.	Ions which are positively charged are called cations. Ions which are negatively charged are called anions.
Example	Example	Example

[edit] Element and Compound

Matter can either exist as an element or a compound.

[edit] Element

• Chemical element is the class of atoms with the same number of protons in the nucleus.
• An element consists of only one type of atom.
• Element can be either atoms or molecules.

[edit] Compound

• A compound is any substance composed of identical molecules consisting of atoms of two or more elements.
• A compound is made up of either molecules or ions.

[edit] The particle theory of matter

The particle theory of matter states that matter is made up of a large number of tiny and discrete particles.

[edit] Diffusion

• Diffusion is a process resulting from random motion of molecules by which there is a net flow of matter from a region of high concentration to a region of low concentration.
• Diffusion is the movement of particles from higher concentration to lower concentration.
• It is a physical process rather than a chemical reaction.
• In diffusion, the particles of one substance mingle and move through the particles of another substance.
• The rate of diffusion is proportional to the average velocity of the particles in matter.

Example of diffusion

[edit] Diffusion in Solid

Before Diffusion	After Diffusion
Copper(II) sulphate crystals are made of copper(II) ions and sulphate ions which are tiny and discrete. The particles in the copper(II) sulphate crystal will separate to become ions and diffuse randomly upwards until the whole agar turns blue. Diffusion of solid is defined operationally as the random movement of particles to all directions in a solid.

[edit] Diffusion in Liquid

Before Diffusion	After Diffusion
Diffusion has taken place in the liquid. The rate of diffusion of the particles in water is faster than the diffusion rate of particles in solid. The occurrence of diffusion proves that potassium permanganate(VII) consist of tiny and discrete particles.

[edit] Diffusion in Gas

Before Diffusion	After Diffusion
Bromine vapour is made of tiny and discrete molecules that move randomly to fill up space. Bromine vapour moves randomly and diffuses in all directions in air from areas of higher concentration to areas of lower concentration.

This video shows diffusion of bromine vapour in air.

Reaction between ammonia gas and the vapour of concentrated hydrochloric acid will produce white fume. This video shows that when 1 drop of ammonia liquid (NH3)is placed near to a drop of concentrated hydrochloric acid (HCl), both the ammonia and hydrochloric diffuse and react to produce white fume. Ammonia will diffuse faster than hydrochloric acid due to its lower mass.

Explanation of diffusion. This flash animation shows how particles diffuse in another medium

[edit] Brownian motion

Brownian motion is the physical phenomenon that minute particles immersed in a fluid move about randomly. It was named for the Scottish botanist Robert Brown, the first to study such fluctuations Brownian movement, an example of diffusion, supports the kinetic theory of matter. Examples of Brownian movement are movement of smoke particles in air movement of pollen grains in water

Galileoandeinstein.physics.virginia.edu, Java applet simulation of rownian Motion. www.phy.ntnu.edu.tw, Java applet simulation of rownian Motion.

[edit] Kinetic Theory of Matter

• The characteristics of matter can be described using the kinetic theory of matter.
• The kinetic theory of matter explains the state of matter in solid, liquid and gaseous states based on the following assumptions:
• The gas consists of very small particles, each of which has a mass.
• These molecules are in constant, random motion. The rapidly moving particles constantly collide with each other and with the walls of the container.
• There are forces of attraction between particles of matter. These attraction forces will increase as the distance between the particles becomes closer.
• The average kinetic energy of the gas particles depends only on the temperature of the system. The higher the temperature, the higher the kinetic energy of the particles.

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Mixture and Compound