Scientists, families, and perodic table Flashcards
Democritus
430 B.C. “atomos”
Dalton’s Atomic Theory
elements that are the same look the same/ elements that are
different look different, one element can’t change into another element,
compounds are 2 or more elements in a ratio
Thomson
discover negatively charged particles electrons
Rutherford
discovered positively charged particles protons and nucleus
Bohr’s Model & Clouds of Electrons
electrons travel in a certain pathway and S, P, D, & F
Modern Atomic Model - Who & When
discovered neutrons so atoms have a nucleus with protons
& neutrons and electrons on the outside (1932 - James Chadwich)
Particle charges
most atoms are neutral so same number of protons and electrons
Isotopes
atoms with different number of neutrons than protons - highly unstable
Dmitri Mendeleev
put elements on notecards and arranged them based on atomic mass, and density to see a pattern did not work
Henry Mosley - Periodic Table & When
arranged the elements based on atomic number -1913
Organization of Periodic Table
Periods (horizontal) Groups (vertical)
Metals (left)
Non-metals (right)
Metalloids (middle)
Nuclear Fusion
2 nuclei combined due to heat or pressure
Metals: Physical Properties
Luster (shiny)
Malleable (flat sheets)
Ductile (run into wire)
High Conductivity (electrons flow through)
Metals: Chemical Properties
Reactivity (easily react with other elements)
Corrosive (rusting)
Alkali metals
Group 1 – react easily to get rid of the 1 electron
Alkaline Earth metals
Group 2 – react easily to get rid of 2 electrons - hard, brittle
Transitional Metals
Group 3-12 / hard and shiny and good conductors
Actinides
Second row of F shell & used as an alloy
Lanthanides
Top row of the F shell & used as an alloy
Nonmetal Properties 4
- Poor Conductors
- Not Malleable
- Not ductile
- Dull
Carbon Family Characteristics
gain, share, lose electrons, chains of carbon in living things - Group 14
Nitrogen Family Characteristics
doesn’t react with other elements, diatomic elements - Group 15
Oxygen Family Characteristics
diatomic element and will easily combined with 2 electrons - Group 16
Halogen Family Characteristics
“salt forming elements” - deadly in pure form very reactive - Group 17