The Sun is a main - sequence star, and thus generates its energy by nuclear fusion of hydrogen nuclei into helium. In its core, the Sun fuses 620 million metric tons of hydrogen each second.
Geography can be understood in five different themes. They are:
• Location
• Place
• Human-Environment Interaction (HEI)
• Movement
• Region
<span>The diversity of functions an organism can hold in its environment, and the diversity of habitats in which it can live. </span>
