The radius of a barium atom is 217 pm. How many barium atoms would have to be laid side by side to span a distance of 3.15 mm?

Question

The radius of a barium atom is 217 pm. How many barium atoms would have to be laid side by side to span a distance of 3.15 mm?

Answer 1

Barium radius 217 pm - how many barium items can be laid side to side to span a distance of 3.15mm.

I'm assuming they are talking about the atomic radius.

Step 1) convert 217 pm to mm.

217pm x 1m/1x10*12pm = 2,17x10-10m

Step 2) convert m to mm

2.17x10-10m x 1x10^3mm/1m = 2.17x10-7mm (atomic radius of a barium atom in mm,

step 3) divide the total span of 3,15mm by the radius of a barium atom in mm

3.15/2.17x10-7 = 1.452x10^7 Barium atoms