The chemical element forms an oxide of the composition e2o, the molar mass is 94 g / mol

The chemical element forms an oxide of the composition e2o, the molar mass is 94 g / mol. Revealing this element, name the qualities inherent in it.

Given:
M (E2O) = 94 g / mol

To find:
NS – ?

Solution:
1) Using the periodic system of D.I.Mendeleev, calculate the atomic mass of an unknown chemical element:
M (E2O) = Mr (E2O) = Ar (E) * N (E) + Ar (O) * N (O);
94 = Ar (E) * 2 + 16 * 1;
Ar (E) = 39;
2) Unknown chemical element – K – potassium;
3) Qualities: alkali metal with typical metallic properties, reactive, strong reducing agent, must be stored in gasoline, kerosene or silicone so that there is no contact with the atmosphere.

Answer: Unknown chemical element – K – potassium.