atomic theory Flashcards
atoms are made up of
protons, neutrons and electrons
electron location:
energy levels outside the nucleus
proton location:
inside nucleus
neutron location:
inside nucleus
electron mass:
nearly 0
proton mass:
1
neutron mass:
1
proton charge:
positive, +1
electron charge:
negative, -1
neutron charge:
none
atomic no. of an elements tells you
how many protons an atom contains
1st energy level can hold
2 electrons
2nd energy level can hold
8 electrons
a period goes
across the period table
groups are
columns in the periodic table
all elements in the same group have
the same no. outer electrons
mass number or an element is equal to
no. of protons + no. of neutrons
isotopes are
atoms with the same atomic no. but different mass no.
nuclide notation arrangement:
atomic no at the top
mass no at the bottom
relative atomic mass (RAM) is
average mass of all the isotopes of a single element
atoms are neutral because
they have an equal no. of positive protons and negative electrons
when the no. of protons and electrons are not equal,
an ion is formed
an ion is
a charged particle that is formed when an atom gains or loses electrons
metals atoms …… electrons to form …
lose electrons to form positive ions
non-metal atoms …… electrons to form..
gain electrons to form negative ions
noble gases have a
stable electron arrangement
