Construction Portal - Sweet-homepl

In 1869, D. I. Mendeleev, based on an analysis of the properties of simple substances and compounds, formulated the Periodic Law: “The properties of simple bodies and compounds of elements are in a periodic dependence on the magnitude of the atomic masses of elements.” Based on periodic

The Periodic Table of the Elements had a great influence on the subsequent development of chemistry. It was not only the first natural classification of chemical elements, which showed that they form a coherent system and are in close connection with each other, but also

Peter the Great is known to every Russian as the great reformer who ruled the country from 1689 to 1725. His reforms, carried out in the first quarter of the eighteenth century, according to historians, moved the country two to five centuries forward. For example, M. Shcher

Types of chemical reactions in inorganic and organic chemistry. 1. A chemical reaction is a process in which other substances are formed from some substances. Depending on the nature of the process, types of chemical reactions are distinguished. 1) According to the final result

The structure of the outer energy levels of atoms of chemical elements determines mainly the properties of their atoms. Therefore, these levels are called valence levels. The electrons of these levels, and sometimes of the pre-external levels, can take part in the formation of chemical

Read the offer in full. We find the basis (or the basis of the proposal). Read what is. If there is only one basis in the sentence → the sentence is simple. If there are two (or more) stems → the sentence is complex. Examples. The field path runs downhill, then again