The space around us is filled with different physical bodies, which consist of different substances with different masses. School courses in chemistry and physics, introducing the concept and method of finding the mass of a substance, were listened to and safely forgotten by everyone who
Let's talk about what is the amount of a substance, how this term is used in natural science subjects. Since quantitative relationships in chemistry and physics are given serious attention, it is important to know the physical meaning of all quantities, their units of measurement
There are many repeating sequences in nature: seasons; time of day; days of the week... In the mid-19th century, D.I. Mendeleev noticed that the chemical properties of elements also have a certain sequence (they say that this idea came
The classification of chemical reactions in inorganic and organic chemistry is carried out on the basis of various classification characteristics, information about which is given in the table below. By change in the oxidation state of elements The first sign of classification is by
The term “covalent bond” itself comes from two Latin words: “co” - together and “vales” - having force, since this is a bond occurring due to a pair of electrons belonging simultaneously to both (or in simpler terms, a bond between atoms behind
1. In which series are the formulas of only alkynes? 3) 2. Based on modern ideas about electron orbitals and their overlap, explain how chemical bonds are formed in the acetylene molecule, and compare them with the chemical bonds in the ethylene molecule
Due to the presence of free electrons (“electron gas”) in the crystal lattice, all metals exhibit the following characteristic general properties: 1) Plasticity - the ability to easily change shape, stretch into wire, and roll into thin sheets.
Not counting those synthesized artificially). All of them are divided into non-metals and metals. There are noticeably more of the latter than the former. Definition of the term Metals in chemistry are elements that occur in nature in the form of simple substances and have
Lecture: Classification of chemical reactions in inorganic and organic chemistry Types of chemical reactions in inorganic chemistry A) Classification according to the number of initial substances: Decomposition - as a result of a given reaction, from one existing complex substance
The periodic table is one of the greatest discoveries of mankind, which made it possible to organize knowledge about the world around us and discover new chemical elements. It is necessary for schoolchildren, as well as for anyone interested in chemistry. Besides,