<span>There is five main area of study in Chemistry, these are:
Analytical, this focusses on experimental equipment and methods used in chemistry (e.g., NMR, Spectroscopic methods, etc.)
Biochemistry - focuses on the chemistry of compounds and processes in living things (e.g., amino acids, proteins, DNA, cellular respiration, Krebs cycle, etc.)
Organic - focuses on the chemistry on most carbon-based molecules found in living things (e.g., hydrocarbons, alcohols, carbolic acids. Amines, ester, etc.)
Inorganic - (focuses on all elements other than carbon (e.g., fluorine, silicon, xenon, etc.)
Physical - focuses on the basic structure and energetic son atoms and molecules (e.g., subatomic structure, is nice and covalent bonding, thermodynamics, reactions, etc.)</span>
Increasing the temperature will cause chemical changes to occur faster. Decreasing the temperature, causes the particles to lose energy which causes them to move around less and slower. The less they move, the less collisions occur, and the less reactions occur between the chemicals = slower reaction rate.
When you see a long dash joining two elements in the structural formula of a chemical molecule you can assume that the chemical bonds in the compound are simple bonds.
In the representation of chemical molecules long dashes are used to represent simple bonds since these bonds are longer than double and triple bonds, which are represented by = and ≡ respectively.