atomic structure and periodic table Flashcards
1
Q
how has the model of the atom changed over the last 200 years?
A
1803, solid atom model, all atoms identical
1904,plum pudding model, atoms are spheres of positive charge with negative electrons
1911, solar system model,positive nucleus
1913, electron shell model
2
Q
how do the parts of atoms compare with eachother?
A
3
Q
why do atoms have no overall charge?
A
protons are +1 and electrons are -1 which cancel eachother out
4
Q
why is most of the mass of an atoms found in its nucleus?
A
the nucleus contains the protons and electrons which contain charges
