01元素和元素周期表
The
umberofproto
si
the
ucleusofa
atomisreferredtoastheatomic
umberorproto
umberZThe
umberofelectro
si
a
electrically
eutralatomisalsoequaltotheatomic
umberZThetotalmassofa
atomisdetermi
edvery
earlybythetotal
umberofproto
sa
d
eutro
si
its
ucleusThistotaliscalledthemass
umberAThe
umberof
eutro
si
a
atomthe
eutro
umberisgive
bythequa
tityAZ
原子核内的质子数被称为原子序数或质子数，Z。一个电中性原子的电子数量也等于原子序数，Z。原子的总质量接近核内质子数和中子数之和。这个总数被称为质量数A。中子在一个原子中的数量中子数给出了的数量为AZ。
Thetermeleme
treferstoapuresubsta
cewithatomsallofasi
gleki
dTothechemistthe