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He said that atoms were uniform, solid, hard incompressible and indestructible and that they moved in infinite numbers through empty space until stopped. -
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He said solid form of matter are composed of invisible elements shaped like triangles. -
It describes atoms as consisting of a nucleus with a number of electrons in orbits around that nucleus. -
The Alchemists believed that all metals were formed from two principles - mercury and sulfur. -
Robert Boyle believed that every thing was composed of very tiny particles. -
He said that matter was composed of atoms that were not created or destroyed during chemical reactions. -
He said that all matter is made of atoms, which are indivisible. -
He said that equal volumes of gas contain equal numbers of molecules and that elementary gases such as hydrogen, nitrogen, and oxygen were composed of two atoms. -
It shows an atom to be a ball-like structure, as the concepts of atomic nucleus and electrons were unknown at the time. -
He said elements arranged according to the value of their atomic weights present a clear periodicity of properties. -
He said all atoms contain tiny negatively charged subatomic particles or electrons. -
He said that some physical quantities only take discrete values. -
He said the frequency of x-ray radiation has a precise mathematical relationship to an elements atomic number. -
They discovered the strongly radioactive elements polonium and radium. -
It shows negatively-charged electrons embedded within a positively charged soup. -
He said any liquid is made of molecules. -
He said electrons have a fixed measurable charge that does not vary. -
He described the atom as having a tiny, dense, and positively charged core called the nucleus. -
He said the behavior of electrons within atoms could be explained by treating them mathematically as matter waves. -
He posited that the way and how the electrons moved was more in a cloud formation, and with the uncertainty principle, he could only predict where an electron might be at any given time. -
It represents the area around an atoms nucleus where electrons are most likely to be found. -
He said that atoms consisted of protons and electrons and another sub-atomic particle called the neutron.