There are two types of atomic bonds-ionic bonds and covalent bonds. They differ in their structure and properties. Covalent bonds consist of pairs of electrons shared by two atoms, and bind the atoms in a fixed orientation. Relatively high energies are required to break them (50â-â200 kcal/mol).
Hummingbirds fly by day when nectar sources such as flowers are more abundant. Flying low allows the birds to see, and stop at, food supplies along the way. They are also experts at using tail winds to help reach their destination faster and by consuming less energy and body fat. Research indicates a hummingbird can travel as much as 23 miles in one day.
Article tools. Using high-speed X-ray cameras, a team of scientists has discovered how hummingbirds manage to fly like insects despite the limitations of their bird skeletons. Most birds produce lift only when they flap their wings downwards, but hummingbirds can do so on the upstroke too by inverting their wings.