lesson 8 the nuclear model Flashcards
the scientist Niels Bohr proposed what
that electrons orbit the nucleus at specific distances rather than just a general area
why was Bohr’s proposal accepted
as it agreed with other scientists’ experiments
what do we now call the orbits
energy levels or shells
several years later, scientists found out that the positive charge in the nucleus is due to what
tiny positive particles which they called protons
what does the number of protons determine
the amount of positive charge in the nucleus
around 20 years after the nuclear model was proposed which scientist made a final important discovery
James Chadwick
what did Chadwick discover
that the nucleus also contains neutral particles which he called neutrons
the radius of an atom is around what
0.1nm (nanometres)
1x10^-10m
what is the radius of the nucleus
1x10^-14
the radius of the nucleus is less than…
1/10000th than the radius of the atom
however nearly all the mass of the atom is found in the nucleus
protons have a relative charge of what
+1
neutrons have a relative charge of what
0
electrons have a relative charge of what
-1
what has no overall charge
atoms
why do atoms have no overall charge
because the number of electrons is the same as the number of protons
