These are the most frequently used words in this book.
abundant
acid
air
alloy
although
aluminium
amount
atmosphere
atomic
atoms
blood
body
bone
calcium
called
carbon
century
chemical
chemist
chloride
comes
compounds
contain
copper
crust
day
discovered
earth
element
environment
environmental
even
first
food
form
found
gas
gold
grams
group
high
however
human
hydrogen
ions
iron
isotope
kilograms
known
lanthanides
lead
less
levels
light
litre
little
may
mercury
metal
milligrams
million
mineral
name
new
now
nuclear
number
ores
oxide
oxygen
part
per
periodic
plants
point
potassium
present
produced
production
radioactive
salts
sea
see
silver
sodium
soils
sulfur
symbol
table
time
tonnes
two
uranium
use
used
water
weight
world
years
zinc