chemistry module 2

• john dalton hypotheses state that: all matter is made up of atoms, atoms of a single element are identical, atoms cant be created or destroyed, atoms of different elements can combine and form compounds, and atoms can be combined, separated, and rearranged in chemical reactions
• j.j. thomson discovered the small, negatively, charged particles in an atom and named them corpuscles (electrons) he said they were randomly scattered in a positively charged atom
• ernest rutherford saw flaws in thomsons theory and proved that atoms are made up of tiny particles called protons and neutrons
• niels bohr worked with rutherford and discovered the nucleus and the electron shells. so the electrons are not randomly scattered
• james chadwick worked under rutherford and suggested that the neutral particle would be called a neutron. concluded that it existed in the nucleus and its mass was very close to a proton
• alkali and alkaline metals are one of the most reactive
• alkali metals are extremely reactive, rare to find alone in nature, and usually combined with other elements
• alkaline earth metals are harder and denser than alkali metals, are less reactive, but still too radioactive to be alone
• transition metals include lanthanides and actinides, can be alone in nature, and are less reacitve
• post transition metals are opaque solids with higher densities and dont conduct heat and electricity as easily as others
• metalloids have properties of both metals and nonmetals
• nonmetals can be solid or gases, include hydrogen, noble gases, and etc.
• halogens are nonmetals known for their high reactivity
• noble gases are unreactive and cant be found naturally reacting with other elements
• lanthanide series are soft, rare-earth metals, are difficult to extract from the environment, silvery in color, and useful for the production of items like glass and lase technology.
• actinide series are all human-made and dont occur in nature, have a silvery white luster in metallic form, and are radioactive