Chemical bonding happens when two or more atoms join together to form a molecule. It is a general principle in science that all systems will try to reach their lowest energy level, and chemical bonding will only take place when a molecule can form that has less energy than its uncombined atoms.hemical bonding happens when two or more atoms join together to form a molecule. It is a general principle in science that all systems will try to reach their lowest energy level, and chemical bonding will only take place when a molecule can form that has less energy than its uncombined atoms.
Human beings were able to create tools around 2.5 million years ago-but we first made bows and arrows 64,000 years ago. The invention of the weapons was a huge leap for our ancestors, enabling them to hunt far more effectively.
Traditional target arrow (top) and replica medieval arrow. Modern arrow with plastic fletchings and nock. An arrow is a fin-stabilized projectile that is shot with a bow, and usually consists of a long straight shaft with a weighty and usually pointed arrowhead attached to the front end, with fletchings and a nock at the rear end. The use of bows and arrows by humans predates recorded history and is common to most cultures.