Elements and the Periodic Table Flashcards
Atom
the smallest particle of an element
in 430 B.C., Democritus proposed the idea that…
Matter is formed of small pieces that can’t be cut smaller
Idea
something that can not be tested
Atomic theory grew because…
of a series of models that developed from experimental evidence
What is Dalton’s Atomic Theory?
-all atoms are composed of atoms that cannot be divided, in the same element atoms are exactly alike and have the same mass unless they are of different elements
-An atom of one element cannot be changed into an atom of a different element
-atoms cannot be created or destroyed, only rearranged in any chemical changed
-every compound is composed of atoms of different element combined in a specific ratio
Electron
a negatively charge particle that has no mass
What is Thomson’s model?
-atoms are made up of even smaller parts
-atoms contain electrons but have no electrical charge themselves, only positive charges
+ and +, or, - and - will…
Repel each other
+ and - will…
Attract each other
What is Rutherford’s Model
-Like charges repelling each other infers that an atom’s positive charge must be clustered in a tiny region in the nucleus
Necleus
An atom’s mass, made up of one or more positively charged particles, located in the center of the atom’s tiny region
Proton
a positively charged particles inside the atom’s nucleus
What is Bohr’s Model
Electrons could have only specific amounts of energy, leading them to move in certain orbits
What is the Cloud Model?
Electrons do not orbit the nucleus and can by found in any cloudlike region around the nucleus
Energy Level
An electron’s movement, that is the specific amount of energy it has
