background

black

chemical

clean

clear

color

corrosive

cream

crystal

danger

drop

education

environment

factory

glass

glove

hand

hot

industry

lab

laboratory

leak

light

liquid

lump

manufacture

material

mix

new

newspaper

research

safety

sample

science

silica

silicate

skin

small

sodium

solid

solution

sticky

substance

symbol

test

top

view

water

wet

white