英文關鍵字
atom
atomic
background
black
category
chemical
chemistry
color
conductivity
configuration
diagram
distribution
education
electron
element
elements
energy
gas
graphic
group
illustration
liquid
malleability
mass
metal
metalloid
molecule
motion
noble
number
oxidizing
particle
period
periodic
physical
proton
reducing
science
scientific
seamless
shell
shells
showing
solid
space
structure
symbol
table
technology
universe
vector
weight
white