What element in the same period as caesium has a smaller atomic radius? What element in the same period as tin has a smaller atomic radius? What element in the same period as gallium has a smaller atomic radius? What element in the same group as arsenic has a larger atomic radius? barium hydrogen lithium sodium none of the above carbon indium iodine strontium none of the above aluminum boron ( potassium selenium none of the above antimony nitrogen () phosphorus potassium none of the above