Before you read this, I suggest you read posts 16.21 and 16.30. A chemical reaction occurs when atoms change the way in which they share electrons to form new molecules (see post 16.30). For example, a carbon atom (C) reacts with an oxygen molecule (O2) to form a molecule of carbon dioxide (O=C=O or CO2).… Continue reading 16.33 Chemical reactions

Many people are optimistic that science will find solutions to the problems that threaten us, like diseases, famines, depletion of natural resources etc. I am an optimist too. But I don’t believe that science can always provide the solution to such problems. For example, suppose I were offered $10billion to recruit a team of scientists… Continue reading 16.32 Faith in Science

Before you read this, I suggest you read posts 16.29 and 16.30. In post 16.30 we saw that the formation of molecules could be explained by atoms sharing pairs of electrons. This shared pair of electrons is called a chemical bond. If two atoms contribute one electron each, the bond is a covalent bond; if… Continue reading 16.31 Electrons in molecules

Before you read this post, I suggest you read posts 16.27 and 16.29 In post 16.29, we saw that electrons occupy atomic energy levels to minimise their overall energy. However, some electron configurations are more stable (they have a lower overall energy) than others. The evidence for this statement is that some atoms are much… Continue reading 16.30 Molecules