Chemistry quiz 1 test notes Flashcards
Democritus
-“matter is composed of tiny, indivisible particles called atoms”
-divides pottery into dust
Aristotle
-matter is made up of earth, air, fire, and water
-bogus, had many followers, put them in bad development
Philosophy vs science
-philosophy comes up with their ideas based on intuition and reason
-science comes up with ideas through experimentation with tools and technology to ask questions
alchemist
-sudo scientists wanting to live forever and get rich with gold
-made graduated cylinder
dalton’s atomic theory
based on works of other scientists who used instruments that were invented to precisely measure mass and volume
- matter is made of indivisible particles called atoms
- atoms of same element are identical (not true cz of isotopes), atoms of different atoms are different
- chemical compounds are formed when atoms combine (no bond!)
- chemical reactions involve the reorganization (breaking & creating) of atoms, but the atoms themselves cannot be created or destroyed (law of conservation of mass)
-billiard ball: atom is a featureless sphere (white ball in pool)
thompson’s experiment
-crooks tube, electric discharge, cathode tube
-ray was composed of a stream of negatively charged electrons
-plum pudding model
-sphere cloud is positively charged with little particles
rutherford
-famous gold foil experiment
-student of thompson and was trying to confirm his theory, however there was unexpected path of light hitting the in closure instead of going straight through the muffin. therefore there is something repelling
-cloud of charged electrons swarming nucleus instead of uniform
chadwick
discovered a neutral particle in the nucleus of an atom or ionb
bohr experiment
-continuous spectrum: produced by passing white light through a prism
-not messy hives, region of space called orbits
-electrons will drop down & back down after given energy
4 main guys for creating atom plus one point for each
- dalton: billiard balls - atoms of …
- thompsons discovery of electron: plum pudding model - uses cathode ray tube to explain how things acquire electrical charge
- rutherfords discovery of the nucleus: thing gold foil sheets
+Chadwicks discovery of neutrons: - confirmed there are neutrons in the nucleus
4.bohr’s proposal of energy levels: directed light through prism with a screen behind it and found random colors produced. led to the proposal that electrons orbit the nucleus of tthe atom in definite energy levels called “planetory model of the atom”
+bohr-rutherford diagrams: used to show number of each subatomic particles in a specific atom and to repersent an arrangement of electrons around nucleus
stable octet
-noble gases are the most stable/unreactive
-full valence shell
cations (positive+)
metals tend to lose electrons to become stable
difference between ions and atoms
1) ions are charged, atoms are not
2) atoms are elements compounds are ions
3) ions are always stable, atoms are reactive
ionization energy
energy that is required to remove an electron from an atom in the process of farming a cation
anions
non metals tend to gain electrons to become stable
electron affinity
-electron affinity energy that is released when an atom gains electrons to become an ion
multivalent ions
-metals can form 2 or more stable ions
-IUPAC naming system uses roman numeral
isotopes
two atoms with the same number of protons (atomic number) but different number of neutrons are called isotopes
-how is the average of Na 23 & 24 22.99? bc there are different allowed values for individual atoms
radioscope
an isotope with unstable nucleus that decays an emits radiation and/or subatomic particles
periodic law
when elements are arranged in order of increasing atomic number, their properties show a periodic recurrence and gradual change
atomic radius
-decreases from left to right
-no additional shielding
-due to nuclear charge increasing, pulling the atoms in making a smaller radius
-increases going down
-adding another orbit (inner electrons shield outer electrons)
ionic radius
-size of ion
-cations are smaller cz they lose a shell + repulsion decreases cz there are less electrons
-anions are larger cause they gain more electrons making the repulsion increase
ionization energy
-energy required to remove an electron from an atom or ion
-increases from left and right because the closer an electron is to the nucleus, the more difficult it is to remove it
-decreases moving down because of the opposite
electron affinity
-increases moving left to right because smaller atoms will have a strong attractive force from the nucleus and a week repulsive force from the electrons cz there are less of them
-decreases moving down cz opposite
