Physical Science
Elements of the Periodic Table
October 9, 2022
Ancient Greeks= Four Elements=Air, Earth, Fire, Water+aether (universe)
18th Century=Boyle, Lavoisier, Berzelius
Robert Boyle=transition from alchemy to modern chemistry in the 18th century
Antoine Lavoisier=proved fire is not an element because it needs oxygen
Jacob Berzelius=chemical element names and symbols
John Newlands=periodic trends=law of octaves=every 8th element by mass
Dimitri Mendeleev=modern periodic table=found new elements by placing gaps and predicting properties
Henry Moseley=used x-rays to study element atomic number and arranged periodic table according to atomic number instead of mass
Organization of Periodic Table=
Columns=families or groups of elements=same number of valence electrons and properties=1-18 and 1A-8A
Rows=1-7=energy levels of electrons
Classifying elements=metals=metalloids=nonmetals
Element families
Alkali metals=left column 1
Alkali earth metals=left column 2
Transition metals=column 3-12
Metals=highly conductive, lustrous, malleable, ductile
Metalloids=Boron (B), Silicon (Si)…, columns 13-16=metalloids=properties of metals and non-metals
Non-metals=Carbon (C), Nitrogen (N), Oxygen (O), Phosphorus (P), Sulfur (S), Selenium (Se)=columns 14-16=poor conductivity
Halogens=column 17=Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I), Astatine
Noble gasses=column 18= Helium (He), Neon (Ne), Argon (Ar) , Krypton (Kr), Xe, Rn
Electron Dot Notation=Element symbol surrounded by valence electrons=column number
Periodic Trends=Atomic number=
Atomic radius=distance from the center of the element nucleus to the outermost energy level=decreases left to right across the table
Electronegativity=ability to attract and hold electrons=increases left to right=downward =decrease=larger atomic radius=smaller electronegativity
Elements of the Periodic Table
October 9, 2022
Ancient Greeks= Four Elements=Air, Earth, Fire, Water+aether (universe)
18th Century=Boyle, Lavoisier, Berzelius
Robert Boyle=transition from alchemy to modern chemistry in the 18th century
Antoine Lavoisier=proved fire is not an element because it needs oxygen
Jacob Berzelius=chemical element names and symbols
John Newlands=periodic trends=law of octaves=every 8th element by mass
Dimitri Mendeleev=modern periodic table=found new elements by placing gaps and predicting properties
Henry Moseley=used x-rays to study element atomic number and arranged periodic table according to atomic number instead of mass
Organization of Periodic Table=
Columns=families or groups of elements=same number of valence electrons and properties=1-18 and 1A-8A
Rows=1-7=energy levels of electrons
Classifying elements=metals=metalloids=nonmetals
Element families
Alkali metals=left column 1
Alkali earth metals=left column 2
Transition metals=column 3-12
Metals=highly conductive, lustrous, malleable, ductile
Metalloids=Boron (B), Silicon (Si)…, columns 13-16=metalloids=properties of metals and non-metals
Non-metals=Carbon (C), Nitrogen (N), Oxygen (O), Phosphorus (P), Sulfur (S), Selenium (Se)=columns 14-16=poor conductivity
Halogens=column 17=Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I), Astatine
Noble gasses=column 18= Helium (He), Neon (Ne), Argon (Ar) , Krypton (Kr), Xe, Rn
Electron Dot Notation=Element symbol surrounded by valence electrons=column number
Periodic Trends=Atomic number=
Atomic radius=distance from the center of the element nucleus to the outermost energy level=decreases left to right across the table
Electronegativity=ability to attract and hold electrons=increases left to right=downward =decrease=larger atomic radius=smaller electronegativity
