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.
Quick Answer. The catapult was invented by engineers working under Dionysios of Syracuse in approximately 399 B.C. The first catapult design was small and closely resembled an early Medieval crossbow that used a released trigger to launch missiles.