Apologia Physical Science Module 3: Atomic Structure
Mendeleev's periodic table
- Russian chemist (1869) - Elements arranged in order of INCREASING MASS. Elements with similar properties fell into groups on the table. 63 Elements known at this time.
Gold Foil Experiment (Rutherford)
-shoots alpha particles (big positively charged particles) -97% of particles went through 2% of particles were slightly deflected 1% of particles came straight back
Dalton's Atomic Theory
1) elements are composed of atoms. 2) atoms of same element are identical, but differ from other elements. 3) elements can mix together 4) atoms only change when mixed with other elements
alpha particle
A cluster of 2 protons and 2 neutrons emitted from a nucleus in one type of radioactivity
Law of Constant Composition
A given compound always contains elements in exactly the same proportion by mass
Aristotle
Aristotle did not believe in the atomic theory and he taught so otherwise. He thought that all materials on Earth were not made of atoms, but of the four elements, Earth, Fire, Water, and Air. He believed all substances were made of small amounts of these four elements of matter.
Bohr's Atomic Model
Atoms have levels surrounding the nucleus where electrons are found. Levels can hold different amounts of electrons depending on their distance from the nucleus.
Isotope
Atoms of the same element that have different numbers of neutrons
Rutherford's model
Concluded atoms consist mostly of empty space where electrons move and also have a positively charged molecule in the center
valence electrons
Electrons on the outermost energy level of an atom
Democritus
Greek philosopher that said all matter is made of tiny particles called "atomos" or atoms
alkali metals
Group 1, 1 electron in outer level, very reactive, soft, silver, shiny, low density; Lithium, Sodium, Potassium, Rubidium, Cesium, Francium
Boron Family
Group 13, 3 valance electrons, both metals and metalloids
Carbon Family
Group 14 with 4 valence electrons containing nonmetals and metalloids. They tend to make covalent bonds
Nitrogen Family
Group 15 with 5 valence electrons nonmetals and metalloids
Oxygen Family
Group 16 with 6 valence electrons.
Periods
Horizontal rows on the periodic table which tells the number of electron shells
Thomsom's Atomic Model
In Thomson's model, the atom is composed of electrons surrounded by a soup of positive charge to balance the electrons' negative charges, like negatively charged "plums" surrounded by positively charged "pudding".
atomic mass (mass number)
The sum of protons and neutrons in the nucleus of an atom
groups of elements
These are the vertical columns on the periodic table. The number of which column the element is in will define its valence electrons of elements with similar properties
Halogens (Group 17)
Very reactive non-metals. Atoms of this group have seen electrons in their outer level.
Electron Cloud Theory
an atom model wherein electrons are no longer depicted as particles moving around the nucleus in a fixed orbit
Erwin Schrodinger
electrons will stay in their patterned dance until they gain energy and speed up (faster and farther from the nucleus). Or lose energy and slow down moving closer to the nucleus-No two electrons can occupy same space
Modern Periodic Table
elements are arranged in order of increasing atomic number
Alkaline Earth Metals
metallic elements in group 2 of the periodic table which are harder than the alkali metals and are also less reactive
subatomic particles
protons, neutrons, electrons
Atom
the basic unit of a chemical element.
noble gases
the elements in Group 8A of the periodic table, they tend to be stable with full electron orbitals
Law of Conservation of Mass
the law that states that mass cannot be created or destroyed in ordinary chemical and physical changes
quatum mechanical model
the modern description, primarily mathematical, of the behavior of electrons in atoms
atomic number
the number of protons in the nucleus of an atom
electron orbitals
volumes of space surrounding the atomic nucleus where electrons are likely to be found