30 terms

science test 1/9/08

Democritus was
John Dalton was from what hundreds?
gases______as if they were made of individual particles
all elements are composed of
what is indivisible and indestructible
atoms of the _______ element are exactly alike
atoms of ___-elements are different
how are compounds formed?
they are formed by the joining of atoms of two or more elements
J.J. Thompson
what did J.J. Thompson say about atoms
he said they are made of smaller particles
what model did J.J. Thompson create?
plum pudding model
what was the plum pudding model
positively charged particles that were like pudding
Ernest Rutherford
what did ernest rutherford discover?
there was a nucleus in an atom
Niels Bohr
Ernest Schrodinger
what did Ernest Schrödinger say about the electrons
it is impossible to determine the exact location of electrons
who said this... mater can not be divided into smaller and smaller pieces forever
who said this... all elements are composed of atoms. they are indivisible and indestructible particles.
John Dalton
who said this... atom is made of pudding like material throughout which negetively (electrons) charged particles are scattered, like plums in a pudding
J.J. Thomson
who said this... all of the positively charged particles (protons) are in the nucleus. electrons are scattered around the nucleus and edge of an atom
Ernest Rutherford
where are protons located?
in the nucleus
where are electrons located
around the nucleus
which model said electrons move in definite orbits around the nucleus?
Bohr model
what does today's atomic model what dos it say about an atom's nucleus
it is a small positively charged nucleus
since the nucleus is surounded by a lot of electrons which have a negative charge, what happens to an atom?
it becomes neutral. it is balanced out between positive charge and negative charge
what are the 3 subatomic particles in alpha order?
electrons, neutrons, protons
neutrons have what charge?
neutral charge
what is the number of protons in the atom called?
atomic number
what is the sum of protons and neutrons in an atom's nucleus?
mass number