Sci Q2 Chapter 1

smallest unit of matter; building block of the universe

the atom consists of three component parts: Protons, Electrons, and Neutrons

JJ Thomson in 1897

Eugen Goldstein in 1886 (Rutherford 1917)

James Chadwick in 1932

Ernest Rutherford in 1911

greek philosopher that said all matter is made of tiny particles called "atomos" or atoms

(billboard) all matter is composed of atoms; atoms cannot be divided

because of his nitric oxide experiment

by using the cathode ray tube

(plum pudding) atoms is made up of electrons floating in protons

(nuclear) atoms have nucleus surrounded by electrons; he discovered nucleus

through gold foil experiment

(planetary) electrons move in fixed orbit (s

through atomic spectra

(quantum model) this doesn't accurately tell us where an electron is

posited the "uncertainty principle" no human could ever determine the path of an electron because observing the electron with light affected the location: we couldn't accurately predict anything physical.

indicated the size of an electron

tells us the shapes of the electron orbitals (sphere

indicates the orientation of an orbital around the nucleus (up or down)

indicate the two fundamental spin states of an electron in an orbital (clockwise/counterclockwise)

it gives us the idea how electrons behave; used to completely describe all the attributes of a given electron belonging to an atom

representation of the arrangement of the electrons distributed among the orbital shells and subshells

s shell: can hold 2 electrons per energy level \n \n p shell: can hold 6 electrons per energy level \n \n d shell: can hold 10 electrons per energy level \n \n f shell: can hold 14 electrons

numbers of electrons are represented by adding a superscript to the sublevel designation

1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 4f 5d 6p 7s 5f 6d 7p

Aufbau Principle; Pauli Exclusion; Hunds rule

electrons fill lower-energy atomic orbitals before filling higher-energy ones. (aufbau - means building up)

states that a maximum of two electrons can occupy a single atomic orbital but only if the electrons have opposite spins

every orbital in a sublevel is singly occupied before any orbital is doubly occupied

tabular display of the chemical elements; it is arranged in increasing atomic number

a charged atom

atomic number - protons; atomic mass - protons and electrons

horizontal arrangement; rows (1-7)

vertical arrangement; column (1-18)

representative elements (s and p elements)

transition elements (d elements)

latanites (57 - 71) and actinites (89 - 103)

group 1A

group 2A

group 7A

group 8A

electrons on the outermost shell

tendency of an atom to attract electrons; non-metals have higher electronegativity

the amount of energy needed to remove an electron from an atom; non-metals have higher ionization energy

atoms tends to prefer to have 8 electrons to be stable; non-metals have higher tendency (we do not consider the f and d electrons)

element surrounded by dots that represent its valence electrons. the number of dots in the Lewis dot symbol is the same as the number of valence electrons, which is the same as the last digit of the element's group number in the periodic table.