Simulation of Newton's Cradle, a device consisting of several steel balls suspended from a cage. Uses the 2D Rigid Body Physics Engine. Each ball acts like an individual pendulum. At rest all the balls are touching.
It was essential to remind people that all the matter around us has one base unit: the atom. Dalton thought it was important to use his system of symbols for the representation of chemical elements because it was helpful to remember exactly which atoms lay at the basic structure of the matter. It was easy for people to use symbols for elements in chemical formulas. He pictured the atoms as small balls and this is the same way that he depicted models of elements and compounds.
Dalton was an English chemist and teacher who used experimental evidence to form the atomic theory of matter: 1  All elements are composed (made up) of atoms. 2  All atoms of the same element are alike. 3  Atoms of different elements are different. 4  Atoms of different elements combine to form a compound. These atoms have to be in definite whole number ratios. For example, water is a compound made up of 2 atoms of hydrogen and one atom of oxygen. (A ratio of 2:1) Three atoms of hydrogen and 2 atoms of oxygen cannot combine to make water. Chemical reactions occur when atoms are separated, joined, or rearranged.