Antonio Lavoisier law of..
law of consecration of mass:
that mass is neither created nor destroyed
- mass of product must = the mass of reactants.
Joseph prost law of
low of definite proportions.
a given compound always contains exactly the same proportions of element by mass.
John dalton law of..
law of multiple proportions
different proportions mean different compound
John Dalton proposed explanations for the laws of mass conservation, definite & multiple proportions:
- all elements is composed of tiny particles called atoms
- chemical reactions only rearrange the way of atoms combine, but dont change the atom themselves
- all atoms of a given element are the same and atoms of different elements are different
- compound always have the same type and number of atoms
to Characterize the Atom: Electron we use..
- cathode ray tube by J.J Thomson
- concluded that
- electrons contain negative charge
- measured the charge/mass
thomson atomic model
like a “plum pudding”.
Robert Millikan
*experiment Electron Charge by using (charged oil drops)
- concluded
- charge/mass
- electron charge
- electron mass
Rutherford’s Atomic Model
- discovered 3 different types of radioactivity: a, b, g
- elpha have the bigger mass
- discoverd the nuclear atom
-Gamma rays (γ)
High-energy light
-Beta particles ()
High-speed electrons
-Alpha particles (α)
Particles with 2+ charge
has bigger mass
The Gold Foil Experiment of rather
- used the alpha particles in a experiment with the discovery of the “nuclear atom”
- used radioactivity beam of alpha particles, in a lead block container
- he used gold because it have simple less atoms
- used a screen to show the elpha particles when it will het it
how Rutherford experiment went and it results
most particles went through straight the gold
some particles where deflected
few particles rebounded
which make us conclude that some atoms contain nuclear which have different charge, that made the elpha particles rebound
ratherfords nuclear model
atoms have nuclear with contain (positive charge) protons and (no charge )neutrons
electrons, protons and neutrons (charge and mass)
Electrons have less mass
-We ignore sometimes the mass of the electrons due its so few mass
-Protons and nuetrons have the mass
-Electrons = protons charge but with oppisite charge
-Mass of atoms= P+N
(JUST IN THE NUCLIEC ATOMS)
nucleus contain
protons and neutrons
Protons:
Have a positive charge that is equal in magnitude to the electron’s negative charge
Neutrons:
Have virtually the same mass as a proton but no charge
what is
- atomic mass
- mass number
- atomic mass
- atomic mass: number of protons
- mass number: total number of protons and neutrons in an atom
- atomic mass: mass of an atom, measured in grams or amu(atomic mass unit)
an ion is
is an atom, or group of atoms, that has a net positive or negative charge.
types of ion and what are they
cation: positive charge, loss charge
anion: negative charge, gain charge
A monatomic ion is..
A polyatomic ion ..
A monatomic ion contains only one atom
A polyatomic ion contains more than one atom
Are Elements in the vertical columns with similar chemical properties ?
yes
group 1 - group 2 - G7 - G8 names
G1: alkali metals (very active element)
G2: alkaline earth metals
G7: Halogen non-metals
G8: noblegases non-metales (little chemical reactivity)
Covalent Bonds
Bonds are forces between atoms by sharing electrons.
Resulting collection of atoms is called a molecule.
what is diatomic molecule and poly Tomic molecule
- A diatomic molecule contains only two atoms
* A polyatomic molecule contains more than two atoms
Ionic Bonds
Bonds form due to force of attraction between oppositely charged ions.
Ion – atom or group of atoms that has a net positive or negative charge.
Cation – positive ion; lost electron(s).
Anion – negative ion; gained electron(s).
