You may not think about it much, but air is everywhere and it is essential to life. Material processes - Solids, liquids and gases - Characteristics of air Learning Points Air is a mixture of gases including nitrogen and oxygen. Air cannot be seen or tasted and has no smell. Air is vital to life on Earth. A Twig Curriculum Film. Delivering key learning points. Get straight to the facts in just three minutes – directly linked to core learning, Twig's curriculum films will fit neatly into your lesson plans.