Question

put these elements in order of smallest to largest atomic volume
arsenic
platinum
helium
tin
fluorine
thallium
sulfur
cesium

Explanation:

Step1: Recall atomic - volume trends

Atomic volume generally increases down a group and decreases across a period in the periodic table.

Step2: Locate elements in periodic table

Helium is in the first period and group 18. Fluorine is in the second period and group 17. Sulfur is in the third period and group 16. Arsenic is in the fourth period and group 15. Tin is in the fifth period and group 14. Platinum is a transition - metal in the sixth period. Thallium is in the sixth period and group 13. Cesium is in the sixth period and group 1.

Step3: Order elements

Based on the trends, the order from smallest to largest atomic volume is: Helium, Fluorine, Sulfur, Arsenic, Tin, Platinum, Thallium, Cesium.

Answer:

Helium, Fluorine, Sulfur, Arsenic, Tin, Platinum, Thallium, Cesium