How is the nitrogen characteristic compiled according to plan? Grade 9 is a course of inorganic chemistry, in which schoolchildren get acquainted with the most important elements of the table of D. I. Mendeleev, as well as with the properties and applications of their compounds. There is a certain algorithm (plan) according to which the ninth-graders are introduced to a representative of a certain group of elements.
Sequencing
What is a characteristic of nitrogen? According to the plan (grade 9, Gabrielyan O.S.), it is first indicated:
- Position in the table of chemical elements. This clause is intended to indicate the group and subgroup, period, valencies and oxidation states, atom structure (number of protons, electrons, neutrons), electronic configuration.
- The next item is a comparison of its chemical properties (the ability to receive and give electrons) with elements neighboring in a group or period. For this, electronic configurations of atoms are made, the radius of each, the number of electrons at the external energy level is taken into account.
- Next, the presence in nature, the main compounds are evaluated.
- When describing physical properties, all modifications (if any) are taken into account.
- When considering the chemical properties of the element being characterized, conditions for the occurrence of interactions are noted.
- An important place is given to the description of the areas of application of the element itself, as well as its most important compounds.
brief information
A general characteristic of the elements of the nitrogen subgroup will help to identify the characteristic physical and chemical properties of all its representatives. Their distinctive feature is the presence at the external energy level of five valence electrons. Representatives of this group may exhibit oxidative properties in chemical interactions. An increase in the radius of the atom from nitrogen to bismuth is observed, as a result of which metal (reduction) abilities are enhanced.
History reference
It complements the nitrogen characteristic as planned. Grade 9 involves preparing students for final certification, including chemistry. In order to ensure the comprehensive development of schoolchildren, historical information can be included in the review.
So how was nitrogen discovered? Chemistry (Grade 9, the author of the textbook is O.S. Gabrielyan) contains useful facts regarding the issue under consideration. In 1772, during the experiments, Rutherford discovered a gas in a glass dome, which he called "suffocating air" due to the inability to maintain combustion and breathing.
In 1787, A. Lavoisier found that nitrogen is an integral part of air. By the beginning of the nineteenth century, its chemical inertness was determined.
Position in the periodic system
Nitrogen is an element of the fifth group (main subgroup) in the table of D. I. Mendeleev. Its relative atomic mass is 14, its serial number is 7. There are seven positive protons and seven neutrons in the nucleus, seven electrons move in two orbits around the nucleus. Nitrogen exhibits the following valencies: II, IV, V, III. Its oxidizing ability is more pronounced than that of phosphorus due to the smaller radius of the atom.
The characteristic of nitrogen according to the plan (Grade 9) assumes the distribution of electrons by energy levels: 2, 5, as well as the formulation of the formula of higher oxide - N 2 O 5 . Given that nitrogen is a chemically inert element, it is rather difficult to obtain this compound. The volatile hydrogen compound is ammonia - NH 3 .
Being in nature
The characteristic of nitrogen according to plan (Grade 9) implies an indication of the main compounds found in nature, as well as the prevalence of nitrogen in the form of a simple substance.
It is one of the most common elements on our planet. In the atmosphere, 78% nitrogen by volume excluding impurities (oxides and ammonia). Of the natural compounds, nitrates (nitrate) are of interest. For a long time, they were used for the industrial synthesis of ammonia.
Nitrogen accumulates in living organisms (in the form of protein compounds) and in the soil. The characteristic of nitrogen according to plan (grade 9) involves a description of the nitrogen cycle in nature. In the textbook of O.S. Gabrielyan there is a scheme according to which students can compose the chemical equations of the processes.
The properties
A general characteristic of nitrogen is an indication of its physical and chemical properties. It is lighter than air, poorly soluble in water, with difficulty liquefying. Nitrogen enters into chemical interaction only with active metals: magnesium, calcium, lithium when heated. As a result of the reaction, nitrides are formed.
Oxides are obtained by exposure to a mixture of ionizing radiation or atmospheric discharges. At high temperatures, nitrogen forms ammonia with hydrogen. Among the products of a similar reaction may include the following substances: hydrazine, octazone.
Receiving and application
Under laboratory conditions, nitrogen is obtained by heating ammonium nitrite. In industry, the separation of liquefied air by distillation is carried out. Most of the nitrogen is used in the industrial synthesis of ammonia, from which fertilizers, nitric acid, and explosive compounds are then obtained.
Free nitrogen is in demand in various branches of modern industry. As an inert medium, it is used in metallurgical and chemical industries. Mercury thermometers are filled with nitrogen. In liquid form, it is used in refrigeration units.
Nitrates (salts of nitric acid) containing bound nitrogen are used in the manufacture of mineral fertilizers for agriculture, as well as explosive compounds.