Chapter 9

This chapter brings reader from the macroscopic world to the microcosmic world. This chapter focuses on molecules and atoms. Here are four properties of molecules: matter is composed of exceedingly small particles called molecules; each different kind of matter is made up of its own particular kind of molecules; molecules are in rapid and ceaseless motion; molecules attract each other. Molecules are made of atoms linked together in definite combinations. A single atom is a kind of miniature solar system. In the center there is a structure called the nucleus. Some negative particles whirling around the nucleus are electrons. Protons and neutrons are found in the nucleus of atoms. The proton has positive charge. In a word, atoms are principally composed of electrons, protons, and neutrons. There are over 100 different kinds of atoms with different chemical properties. They are named elements. Some familiar elements include the following: hydrogen, helium, lithium, carbon, nitrogen, oxygen, fluorine, neon, sodium, magnesium, aluminum, silicon, phosphorus, sulfur, chlorine, argon, potassium, calcium, iron, nickel, copper, silver, tin, iodine, platinum, gold, mercury, lead, radium, and uranium. Alchemists dreamed of transmuting one element into another; however, none of them succeeded.

There are too many scattered things and properties to pick up. I just record as many as possible. In physical changes the composition of molecules is not changed, whereas in the chemical changes the composition of molecules is altered. Three factors essential for burning are a supply of oxygen, a supply of fuel, and enough heat to raise the fuel to its kindling point. Extinguish fire is based on the elimination of one or more of the three factors essential for burning.

The paragraphs are so randomly written; nevertheless, I don’t want to revise any more. I just leave them there.