Chapter 2 Atoms and Periodic Table Flashcards
1 of Daltons Theory
All elements are composed of atoms – small, indivisible and indestructible particles.
2 of Daltons Theory
All atoms of the same element are exactly alike
3 of Daltons theory
Atoms of different elements are different.
4 of Daltons theory
The atoms that make up a cmpd. are in a definite proportion.
Law of Definite Composition
A compound always contains 2 or more elements combined in a definite ratio
Law of Multiple Proportions
: Atoms of 2 or more elements may combine in different ratios to produce more than one cmpd.
Thomsons model is the
plumb pudding model
What did rutherford do
Gold foil experiment
What was the gold foil
Alpha particles are a form of matter and are positively charged
Atoms made empty space
small dense central nucleus
Bohr figure out
negative particles exist in orbit
Chadwick
Neutron
Atomic number is
protons and electrons
Proton
p+ , 1 amu , +1 charge
Neutron
n0, 1 amu , no charge
electron
e- , about 0 , -1
1 amu is equal to
1/12 the mass of carbon -12 atom
max number electron pattern
2-8-18-32
isotopes
Atoms of the same element that contain the same # of p+ and e-, but different # of no. As a result, they have different masses.
All element is group 1 react
violently
Lanthanoids
Top
rare earth metals
Actinides
Bottom
radioactive
Alkali earth metals
Group 1,Shiny, soft, and low melting point metals
All react rapidly with water to form flammable H2 gas and alkaline or basic solutions.
Alkaline earth metals
Group 2Lustrous, silvery metals
React with O2
They are less reactive to water than the alkali metals.
Halogens
Group 17Colorful and corrosive nonmetals
All are found in nature in combination with other elements, such as with sodium in sodium chloride (NaCl
