He

(a)  

Li

(a)  

Be

(a)  

B

(a)  

C

(a)  

N

(a)  

O

(a)  

F

(a)  

Ne

(a)  

Na

(a)  

Mg

(a)  

Al

(a)  

Si

(a)  

P

(a)  

S

(a)  

Cl

(a)  

Ar

(a)  

K

(a)  

Ca

(a)  

Sc

(a)  

Ti

(a)  

I

(a)  

Cr

(a)  

Mn

(a)  

Fe

(a)  

Co

(a)  

Ni

(a)  

Cu

(a)  

Zn

(a)  

Ga

(a)  

Ge

(a)  

As

(a)  

Se

(a)  

Br

(a)  

Kr

(a)  

Sr

(a)  

Ag

(a)  

Sn

(a)  

Ba

(a)  

Au

(a)  

Hg

(a)  

Pb

(a)  

U

(a)  

symbol for hydrogen

(a)  

symbol for helium

(a)  

symbol for lithium

(a)  

symbol for beryllium

(a)  

symbol for boron

(a)  

symbol for carbon

(a)  

symbol for nitrogen

(a)  

symbol for oxygen

(a)  

symbol for fluorine

(a)  

symbol for neon

(a)  

symbol for sodium

(a)  

symbol for magnesium

(a)  

symbol for aluminum

(a)  

symbol for silicon

(a)  

symbol for phosphorus

(a)  

symbol for sulfur

(a)  

symbol for chlorine

(a)  

symbol for argon

(a)  

symbol for potassium

(a)  

symbol for calcium

(a)  

symbol for scandium

(a)  

symbol for titanium

(a)  

symbol for iodine

(a)  

symbol for chromium

(a)  

symbol for manganese

(a)  

symbol for iron

(a)  

symbol for cobalt

(a)  

symbol for nickel

(a)  

symbol for copper

(a)  

symbol for zinc

(a)  

symbol for gallium

(a)  

symbol for germanium

(a)  

symbol for arsenic

(a)  

symbol for selenium

(a)  

symbol for bromine

(a)  

symbol for krypton

(a)  

symbol for strontium

(a)  

symbol for silver

(a)  

symbol for tin

(a)  

symbol for barium

(a)  

symbol for gold

(a)  

symbol for mercury

(a)  

symbol for lead

(a)  

symbol for uranium

(a)