Atoms, ions, and molecules Flashcards
key points of Dalton’s atomic theory
- all matter consists of atoms
- atoms of the same element have the same properties; atoms of different elements have different properties.
- compounds are formed by different ratios of atoms
- atoms cannot be created or destroyed in chemical reactions.
Law of conservation of mass
The total mass at the beginning of the reaction is the same as the total mass at the end of the reaction (1 to 1 ratio)
law of definite properties
All molecules of the compound will have the same mass ratio between all its elements
law of multiple proportions
when two elements combine to form more than one compound, the mass ratios are simple whole numbers
what did the cathode ray experiment demonstrate about electrons?
cathode rays are streams of negatively charged particles (electrons) and helped determine the mass-to-change ratio of electron.
what was discovered from Rutherford’s Gold Foil experiment?
the experiment revealed that atoms have a small, dense, positively charged nucleus
dalton
solid sphere model
thomson
plum pudding model
Rutherford
nuclear model
bohr
solar system model
chadwick
proton-neutron model
what are isotopes
atoms of the same element with the same number of protons but different number of neutons
how is atomic mass calculated
atomic mass = protons + neutrons
what are periods and groups in the periodic table?
periods- horizontal rows
groups- vertical columns
elements in the same group, have similar chemical properties.
difference between molecular and empirical formulas?
molecular formula- shows actual number of atoms in a molecule.
empirical- shows lowest whole number ratio of atoms in a molecule.
what are the rules for naming binary molecular compunds?
- first element keeps its full name
- the second element takes the root+ “-ide”
- prefixes indicate the number of atoms (mono, di, tri, etc.)
- “Mono-“ is not used for the first element.
what is the difference cations and anions?
cations- positively charged ions formed when metals lose electrons
anions- negatively charged ions formed when non-metals gain electrons
how do ionic compounds form?
formed when electrons are transferred from one atom to another, creating a bond between a cation and an anion.
how are binary ionic compounds names
the cation is named first, followed by the anion with the suffix “-ide”
how are transition metals named in ionic compounds?
the cation is named first with its change indicated by roman numerals
(ex. FeCl3= iron (111) chloride)
how are acids named?
based on the anion they produce when dissolved in water (ex. H2SO4 = sulfuric acid)
