This article discusses the production of alkyl- and acylbenzenes by the Friedel-Crafts reaction, which are indispensable components of various building materials, as well as fuels and many surfactants. From a substance such as toluene, nail polishes are obtained, and, for example, xylene is a component of building solvents. Last modified: 2025-06-01 07:06
Secondary education and schools
Those who are just starting to get acquainted with chemistry and its inherent types of designation of various substances and equations need to know certain rules used in international practice. The following examples will help you understand what the entries 3H, 2H2O, 5O2 mean and what information is obtained from this set of numbers and letters. Last modified: 2025-01-23 12:01
Biological interspecies competition is a natural process of struggle between different individuals for space and resources (food, water, light). It occurs when species have similar needs. Another reason for the start of competition is limited resources. Last modified: 2025-01-23 12:01
The profession of a journalist is one of the most preferred by today's youth. Preparing for admission to a university should begin already in high school. The School for Young Journalists at Moscow State University is a creative laboratory that allows its students to get to know their future profession as much as possible, prepare for admission and even have a little practice in the editorial offices of famous newspapers and magazines. Last modified: 2025-01-23 12:01
Deserts, wild animals, savannas and many tribes with authentic customs are the first images that come to mind when thinking about Africa. In fact, it is a very developed continent with a huge variety of cultures, languages and attractions. Last modified: 2025-01-23 12:01
Algeria is a country located in North Africa. It belongs to the states of the Mediterranean basin, and also has access to the sea in the north. Official name - People's Democratic Republic of Algeria. Last modified: 2025-01-23 12:01
The work of Alexander Isaevich Solzhenitsyn, whose biography will be presented to your attention in the article, can be treated in completely different ways, but it is worth unambiguously recognizing his significant contribution to Russian literature. In addition, Solzhenitsyn was also a fairly popular public figure. For his handwritten work The Gulag Archipelago, the writer became a Nobel laureate, which is a direct confirmation of how fundamental his work has become. Last modified: 2025-01-23 12:01
Is Algiers a city or a country? Not everyone knows the answer to this question. Our article will exhaustively answer it. In addition, here you will find interesting information about the largest cities of the largest African state by area. Last modified: 2025-01-23 12:01
Throughout its long path of existence and development, man has been prone to research, study, discovery. He did a lot to simplify his life, made a lot of efforts to reveal the meaning of his existence, any laws and causes of natural phenomena. Last modified: 2025-01-23 12:01
A reasonable man has been living on the Earth for more than one thousand years. During this time, a lot has happened - entire empires and kingdoms have risen and fallen, new states have appeared, technologies have been actively developed. At the same time, if you look at history from the side of an individual, you can see his desire to unite with others like himself. Last modified: 2025-01-23 12:01
The article reveals the main functions and role of a teacher in the life of every person. The main directions of such interaction are determined. Last modified: 2025-01-23 12:01
Explosions can come in many forms and types: from pieces of a bursting balloon flying in different directions to a huge mushroom of death caused by a nuclear bomb. Therefore, if you want to draw an explosion, then you first need to decide what it will be, and then get to work. Last modified: 2025-01-23 12:01
What is a baby doll? In speech, this amazing word occurs from time to time. But what does it mean? This article presents the dictionary meaning of the word pupsik. It also indicates what part of speech it is. The etymology of the word is given, as well as examples of sentences. Last modified: 2025-01-23 12:01
Many of us remember Archimedes from school. It was the one who said "Eureka!" after entering the tub and noticing that the water level had risen. This led him to realize that the volume of water displaced must be equal to the volume of the object being submerged. Last modified: 2025-01-23 12:01
Phonetics and orthoepy are closely interconnected. These sciences are large sections of linguistics. Last modified: 2025-01-23 12:01
Everyone came across geographical maps at school. However, not all of us have an idea about their purpose and know how to use them. Modern youth believes that they do not need this knowledge, since navigators are now widespread. Last modified: 2025-01-23 12:01
Water is the basis of life on the planet, and rivers are often the main source of water for most people. That is why studying them is so important and interesting. Last modified: 2025-01-23 12:01
The word "code" is usually understood as a set of symbols, signs and rules for providing various data. For high-quality data transmission, information is encoded and processed according to certain algorithms. Last modified: 2025-01-23 12:01
After reading the fairy tale about the almighty Frog Princess, the children get the task: to write an essay on the topic “Characteristics of Ivan Tsarevich”. In order to cope with this task, it is necessary to remember what this wonderful story is about. Last modified: 2025-01-23 12:01
Autumn is such a period in the life of nature, when everything around is in the last bright colors and falls asleep for the winter. However, we should not be sad, because there are still three whole months of autumn ahead, the last warm days and rains. In the fall, all children go to school, their parents go back to work, and life goes on as usual. But we can’t be sad, we can have fun and “stretch” the brains that have relaxed over the summer. Last modified: 2025-06-01 07:06
There is always an excuse. There would be a suggestion. So said Erich Maria Remarque. We will talk about prepositions in this article. Last modified: 2025-01-23 12:01
Currently, there are about a thousand cities on the territory of the world's largest state. All of them differ from each other in terms of population and area. Last modified: 2025-01-23 12:01
The article is devoted to the economy. Different types of economic activity, their features and common features are considered. Last modified: 2025-01-23 12:01
The world of insects is the most extensive on the planet. The life of these little creatures is as amazing and diverse as the life of other creatures, and thanks to this, you can write many stories about insects that will appeal to both adults and children. So how do you write an interesting little story about insects?. Last modified: 2025-01-23 12:01
Rarely anyone in our time can be called a "clerical rat", yet not the most common phrase, and everyone's tongue has become sharper and angrier. But nevertheless, if you were called - is it worth being offended? Do I need to somehow respond to this or can I let the offender get away with it? Yes, and rats, in general, are cute animals, if they are domestic … So be offended or not?. Last modified: 2025-01-23 12:01
When choosing different topics for essays, it is worth considering not only its genre. The main assistant in this matter is the main theme or thought. It is on it that the structure of the text and the style of writing the essay are chosen. But what is the main idea based on? Key words are the foundation of all foundations. It is very important to help children understand what it is. Last modified: 2025-01-23 12:01
The warm current is the Gulf Stream, El Niño, Kuroshio. What other currents exist? Why are they called warm? Read more about it. Last modified: 2025-01-23 12:01
In 1827, English biologist Robert Brown observed through a microscope a drop of water containing a small amount of pollen. He saw that the smallest particles of pollen were dancing, moving chaotically in the liquid. So the Brownian movement named after this scientist was discovered. Last modified: 2025-01-23 12:01
Rigid body physics is the study of many different types of motion. The main ones are translational movement and rotation along a fixed axis. There are also their combinations: free, flat, curvilinear, uniformly accelerated and other varieties. Each movement has its own characteristics, but, of course, there are similarities between them. Consider what kind of movement is called rotational and give examples. Last modified: 2025-01-23 12:01
Some substances, participating in chemical reactions, have the ability to emit light. Every amateur chemist at least once made a luminous liquid. This article will discuss what luminol is, how to prepare it at home. Last modified: 2025-01-23 12:01
The capital of California - Sacramento, the photo of which you can see in the article - is an American city located on the territory of the United States of America. It is located in the western part of the mainland along the banks of the American River. Its coordinates: 38°34′31″ s. sh. 121°29′10″ W d. Last modified: 2025-01-23 12:01
Al2(SO4)3 - aluminum sulfate, an inorganic substance from the class of s alts. Occurs in the form of crystals or white powder, soluble in water. A chemically active substance that reacts well with many components, therefore it is often used in experiments and tasks in chemistry, but to solve them you need to know the molar mass of Al2 (SO4) 3. Last modified: 2025-01-23 12:01
The article discusses the main methods for studying the density of matter in the 7th grade of high school. An analysis was made of the use of theoretical and experimental methods of teaching physics. Last modified: 2025-01-23 12:01
Atmosphere is a gas cloud that surrounds the Earth. The weight of air, the height of which exceeds 900 km, has a powerful effect on the inhabitants of our planet. Last modified: 2025-06-01 07:06
A system of two conductors separated by a dielectric layer is a capacitor. It is designed to accumulate charge and quickly discharge it through the conductor. Capacitor energy is widely used in engineering. Last modified: 2025-01-23 12:01
The article considers galvanic cells as sources of direct current. Design features and ease of manufacture make them indispensable in various techniques. Last modified: 2025-06-01 07:06
Electrical voltage is measured for various purposes, but the value of this quantity in technology is always taken into account. Last modified: 2025-01-23 12:01
This publication is dedicated to the set expression "Gerostrat's glory". The article discusses the meaning, the history of the origin of a phraseological unit, provides examples of its use. Last modified: 2025-01-23 12:01
Today, the idiom "to shoe a flea" can be heard quite rarely. Fortunately, this original fixed expression, introduced into use with the light hand of the writer Leskov at the end of the 19th century, was not completely forgotten. In what cases do people remember a vivid turn of speech, what meaning is traditionally attached to it?. Last modified: 2025-01-23 12:01
What are benefits? Good question. Especially now, when people are concerned about their strengths and weaknesses. It is necessary to be able to maneuver and turn shortcomings into advantages. Today we will analyze the meaning of the word. Last modified: 2025-01-23 12:01