What is the mass, in kilograms, of formula units of barium chloride?

≈ 8.51E-5 kg

Explanation:

First take the mass of BaCl2, and multiply by the ratio between 1 mol of formula units which is around 6.02 × 10^23, and the formula units given, which are 2.46 × 10^20.

This ratio as a decimal is around

2.46 × 10^20. ÷ 6.02 × 10^23 = 0.000408637873.

The final step is to multiply this ratio by the mass in grams, and divide by 1000 to convert to kilograms.

So

0.000085091890208409

oxygen, selenium, tellurium, and polonium.

they're all from the same group as sulfur (group 16).