1. It would be better if you used subscript in chemical formulas instead of normal numbers. Subscripts are supported by Unicode and using them is the proper way of writing chemical formulas
2. It would be better if you used arrows instead of the equal sign. Equal sign suggests that the sides are identical, which is not the case with chemical equations.
3. There are some typos of the test. For example in the question about Napoleon "Он умер отравивись этим веществом." should be "Он умер отравившись этим веществом" and so on.
4. Some descriptions are copied. For example "Ионная связь — сильная химическая связь, возникающая в результате электростатического притяжения катионов и анионов." is copied from https://ru.wikipedia.org/wiki/Ионная_связь
5. In a question asking about the sum of coefficients in chemical equation it would be better to include the overall equation in your explanation.
2. It would be better if you used arrows instead of the equal sign. Equal sign suggests that the sides are identical, which is not the case with chemical equations.
3. There are some typos of the test. For example in the question about Napoleon "Он умер отравивись этим веществом." should be "Он умер отравившись этим веществом" and so on.
4. Some descriptions are copied. For example "Ионная связь — сильная химическая связь, возникающая в результате электростатического притяжения катионов и анионов." is copied from https://ru.wikipedia.org/wiki/Ионная_связь
5. In a question asking about the sum of coefficients in chemical equation it would be better to include the overall equation in your explanation.