atomic structure Flashcards
what is an atom?
a fundamental piece of matter
the basic unit-the smallest particle of a chemical element
what are the models that have been proposed for the atomic structure?
Thomson’s plum pudding model
rutherford model
Bohr model
what was Thompson’s model (atomic structure)?
it was the Plum Pudding Model, where the negatively charged electron was covered in a batter of positive charges.
what was the rutherford model?
he proposed the central nucleus
what was bohrs model?
similar to the one we use now
what is the nucleus composed of?
protons and neutrons
what are some features of the nucleus?
it is in the centre of the atoms
tiny
dense
what are some key features of the electrons?
they orbit the nucleus in shells
do not contribute much to the mass of the atom
what is the relative charge of the proton?
+1
what is the relative charge of the neutron?
0
what is the relative charge of the electron?
-1
what is the relative mass of the proton?
1.0
what is the relative mass of the neutron?
1.0
what is the relative mass of an electron?
1/2000
why are the atoms normally neutral?
Because the negative electron charges cancel out the positive proton charges
