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.
The small cross-bow, called the arbalet or arbalest, is said to have been invented by the Sicilians. It was carried by the foot-soldiers, and when used was charged with a quarrel or bar-bolt, that is, a small arrow with a flat head, one of which occasioned the death of Harold at the battle of Hastings, [â¦]. 2000.