alert
atomic
bacterium
beaker
biology
bright
caution
chemistry
color
colorful
contour
danger
disease
energy
flask
germs
glass
glowing
hazard
icon
illness
illustration
infection
isolated
light
line
linear
medical
medicine
micro
microbe
microbiology
neon
nuclear
organism
outline
pollution
power
radiation
radioactivity
safety
science
set
sign
symbol
toxic
virus