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