Answer:
helium Because it's in the 9th grade book
Answer:
Terms in this set (13)
Hydroxide. OH.
Nitrate. NO3.
Ammonium. NH4.
Bicarbonate/Hydrogen Carbonate. HCO3.
Bisulphate. HSO4.
Chlorate. ClO3.
<h2>hope it's correct</h2>
The smallest atomio radius is helium
