«APPROVE»
Teacher______________
«…» ____________2022
Lesson-plan
Discipline: «Modern technologies in chemical education »
Topic: «Nonmetals»
Date of the lesson: 31.10.2022
Prepared: Tukenova Lazzat
1 course, M013
__________
Score: ______
Signature of the teacher: __________
Purpose: To form students' knowledge about the nonmetals.
Тип: Announcement lesson.
Time: 2 hour.
PLAN
1. Organizational moment
2. Learning new material
*Nonmetals
*Halogens
*Noble gases
*Feedback
3. Homework assignment
4. Conclusion
REFERENCES
1) Ripan R. Inorganic chemistry: В 2-х v./Р. Ripan, I. Chetyanu; Perev. c rum. D.G. Batyra,
H.M. Kharitona; Under ed. V.I. Spitsyna, I.D. Collie. - M.: Izdatelstvo "Mir" 1972. - 2 volumes.
2) Knunyants I.L. Short chemical encyclopedia: Vol. 5. / Ed. col. I.L. Knunyants (Otv. ed.) and
others. - M.: Publishing House "Soviet Encyclopedia", 1967 - 5 volumes.
3) Lidin, R.A. Chemical properties of inorganic substances: учеб. allowance for universities /
R.A. Lidin, Molochko, LL Andreeva. Under ed. R.A. Lidina. - M.: Khimiya, 2000 - 480 p.
4) Nekrasov B.V. Basic General Chemistry T. I. izd. 3rd, ex. and the ball. Publishing house
"Khimiya", 1973 - 656 p.
Time
Lesson plan
Theme of the lesson: ‘Nonmetals’
The purpose of the lesson:
*to describe the location of nonmetals in the periodic table;
* to list the general properties of nonmetals and acknowledging common exceptions;
* to describe structural properties of nonmetals.
Basic concepts: nonmetals, solids, liquids, gases, poor conductors, brittle etc.
3 min
Lesson progress:
I. Organizational moment
Greeting! Setting the goals and objectives of the lesson.
30 min
II. Learning new material
Non-metal elements are simply the elements that are not metals, and include hydrogen,
carbon, nitrogen and oxygen. They are found on the right-hand side of the periodic table,
and can be solids, liquids or gases at room temperature, as they vary widely in melting
point and boiling point, from very high (carbon) to very low (helium).
At room temperature some are solids (carbon, silicon, phosphorus, sulphur, iodine), one
is a liquid (bromine), but most are gases. They are nearly all poor conductors of heat and
electricity. The solid non-metal elements are brittle.
Compounds containing oxygen and non-metals (the oxides of non-metals) are either
acidic in aqueous solution (carbon dioxide, sulphur dioxide, nitrogen dioxide,
phosphorus pentoxide) or neutral (carbon monoxide, water, nitrogen monoxide). The
atoms of the non-metal elements are the fundamental building blocks of all biological
molecules. Proteins, nucleic acids, starches, sugars, fats and vitamins are composed of
non-metal elements. They are the chemical basis of all life on Earth, whether plants,
animals, fungi, protists or bacteria. The enormous diversity of these compounds stems
from the amazing ability of carbon atoms to form large, complex, stable molecules.
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member
of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing
agent that readily forms oxides with most elements as well as with other compounds.
Oxygen is Earth's most abundant element, and after hydrogen and helium, it is the thirdmost abundant element in the universe. At standard temperature and pressure, two atoms
of the element bind to form dioxygen, a colorless and odorless diatomic gas with the
formula O2. Diatomic oxygen gas currently constitutes 20.95% of the Earth's
atmosphere, though this has changed considerably over long periods of time. Oxygen
makes up almost half of the Earth's crust in the form of oxides
Chemical properties.
Oxygen therefore oxidizes metals to form salts in which the oxygen atoms are formally
present as O2- ions. Rust forms, for example, when iron reacts with oxygen in the
presence of water to give a salt that formally contains the Fe3+ and O2- ions, with an
average of three water molecules coordinated to each Fe3+ ions in this solid.
H2O
4 Fe(s) +3 O2 (g) ----->2 Fe2O3 (s) + 3 H2O
Oxygen also oxidizes nonmetals, such as carbon, to form covalent compounds in which
the oxygen formally has an oxidation number of -2.
C(s) +O2 (g) ----->CO2 (g)
Oxygen reacts with hydrogen to produce two compounds: water ( H2O ) and hydrogen
peroxide ( H2O2 ). Water is a versatile compound and participates in acid-base
equilibrium and oxidation-reduction reactions. It can act as an acid, base, reducing agent,
or oxidizing agent. Water's multifaceted abilities make it one of the most important
compounds on earth. The reaction between hydrogen and oxygen to form water is given
below:
2H2(g) +O2(g)→2H2O
Hydrogen peroxide's potent oxidizing abilities give it great industrial potential. The
following equation shows the reaction of hydrogen and oxygen to form hydrogen
peroxide:
H2+O2→H2O2
The product of this reaction is called a peroxide because oxygen is in the O2−2 form
(hydrogen has a +1 oxidation state).
Sulfur's reaction with oxygen produces the oxides Sulfur dioxide, SO2, and sulfur
trioxide, SO3, are the only common sulfur oxides. All are powerful oxidizing agents.
SO2 is mainly used to make SO3
Δ
S(s)+O2 (g) → SO2(g)
2SO2 (g)+O2 (g)⇌2SO3 (g)
Nitrogen (pronounced as Nye-treh-gen) is a chemical element, existing in the form of a
colorless diatomic gas. Denoted by the chemical symbol N, it belongs to the family of
nonmetals. It is the fifth most abundant element in the earth’s crust, represented by the
molecular formula N2 . There are 12 isotopes of nitrogen with masses ranging from 11
to 19 of which only N-14 and N-15 occur naturally.
In the earth’s atmosphere, it constitutes about 78% of the air that is estimated to be around
4000 trillion tons. It is extracted from the liquefied air through fractional distillation.
Chemical properties.
Nitrogen bonds to almost all the elements in the periodic table except the first three noble
gases, helium, neon, and argon, and some of the very short-lived elements after bismuth,
creating an immense variety of binary compounds with varying properties and
applications. Many binary compounds are known: with the exception of the nitrogen
hydrides, oxides, and fluorides, these are typically called nitrides. They are normally
prepared by directly reacting a metal with nitrogen.
3Ca + N2 → Ca3N2
Nitrogen can be brought to react with hydrogen. This is called the Haber process
400-500 °C
Fe catalyst
N2(g) + 3 H2 (g) ↔
2 NH3(g)
High pressure
The halogens fluorine, chlorine, bromine, and iodine are nonmetals. Halogens are
diatomic, which means they form molecules of two atoms. In nature, halogens always
exist as F2, Cl2, Br2, I2 and At2. The halogens show trends in chemical bond energy
moving from top to bottom of the periodic table column with fluorine deviating slightly.
It follows a trend in having the highest bond energy in compounds with other atoms, but
it has very weak bonds within the diatomic F2 molecule. This means that further down
group 17 in the periodic table, the reactivity of elements decreases because of the
increasing size of the atoms.
Halogens are highly reactive, and as such can be harmful or lethal to biological
organisms in sufficient quantities. This high reactivity is due to the high electronegativity
of the atoms due to their high effective nuclear charge. Because the halogens have seven
valence electrons in their outermost energy level, they can gain an electron by reacting
with atoms of other elements to satisfy the octet rule. Fluorine is the most reactive of all
elements; it is the only element more electronegative than oxygen, it attacks otherwiseinert materials such as glass, and it forms compounds with the usually inert noble gases.
It is a corrosive and highly toxic gas. The reactivity of fluorine is such that, if used or
stored in laboratory glassware, it can react with glass in the presence of small amounts
of water to form silicon tetrafluoride (SiF4).
Z
9
17
35
53
Element
fluorine F
chlorine Cl
bromine Br
iodine
I
No. of electrons/shell
2, 7
2, 8, 7
2, 8, 18, 7
2, 8, 18, 18, 7
Fluorine (F2) and chlorine (Cl2) are gases at room temperature. Bromine (Br2) is a
reddish-brown liquid at room temperature and is—apart from mercury—the only
element that is liquid at 20 °C (68 °F) and atmospheric pressure. Iodine (I2) forms dark
violet crystals under these conditions. In the solid state the halogen elements form
molecular lattices, and the sublimation energies rise with increasing size of the
molecules.
The halogen atoms carry seven valence electrons in their outermost electron shell. These
seven outermost electrons are in two different kinds of orbitals, designated s (with two
electrons) and p (with five). Potentially, a halogen atom could hold one more electron
(in a p orbital), which would give the resulting halide ion the same arrangement
(configuration) as that of the noble gas next to it in the periodic table. These electron
configurations are exceptionally stable. This pronounced tendency of the halogens to
acquire an additional electron renders them strong oxidizers.
Chemical properties. In general, halogens have high electronegativities - fluorine is the
most electronegative element in the periodic table. Their electronegativity decreases as
you go down the group. Their reactivity also decreases as you go down the group.
Halogens all take part in similar reactions. For example, they react with metals to form
salts and with hydrogen to form hydrogen halides. Halogens are sparingly soluble in
water, tend to form negative anions, and are found as diatomic molecules.
Probably the most important generalization that can be made about the halogen elements
is that they are all oxidizing agents; i.e., they raise the oxidation state, or oxidation
number, of other elements—a property that used to be equated with combination with
oxygen but that is now interpreted in terms of transfer of electrons from one atom to
another. In oxidizing another element, a halogen is itself reduced; i.e., the oxidation
number 0 of the free element is reduced to −1.
The halogens can combine with other elements to form compounds known as halides—
namely, fluorides, chlorides, bromides, iodides, and astatides. Many of the halides may
be considered to be salts of the respective hydrogen halides, which are colourless gases
at room temperature and atmospheric pressure and (except for hydrogen fluoride) form
strong acids in aqueous solution. Indeed, the general term salt is derived from rock salt,
or table salt (sodium chloride). The tendency of the halogen elements to form saltlike
(i.e., highly ionic) compounds increases in the following order: astatine < iodine <
bromine < chlorine < fluorine. Fluorides are usually more stable than the corresponding
chlorides, bromides, or iodides. (Often astatine is omitted from general discussions of
the halogens because less is known about it than about the other elements.)
The oxidizing strength of the halogens increases in the same order—i.e., from astatine
to fluorine. Therefore, of the halogen elements, elemental fluorine is prepared with the
greatest difficulty and iodine with the least. As a class, the halogen elements are
nonmetals, but astatine shows certain properties resembling those of the metals.
A more reactive halogen displaces a less reactive halogen from a solution of its halide.
Example: When chlorine is added to a potassium iodide solution, the more reactive
chlorine will replace the less reactive iodine.
Cl2 + 2KI → I2 + 2KCl
When bromine is added to a sodium fluoride solution, no reaction will occur since
bromine is less reactive than fluorine.
Uses of Halogens.
Bromine and chlorine are often used as disinfectants for purifying water, swimming
pools, fresh wounds, dishes and sterilizing surfaces.
Small amounts of a halogen such as iodine or bromine are found in Halogen lamps.
Fluoride is found in products such as toothpaste, baby formulas and vitamin
supplements.
Chlorine accounts for about 0.15 percent of human body weight and plays several
important roles in the body’s functioning. Compounds of both chlorine and bromine
are used as disinfectants for sterilization.
Fluoride anions are found in some quantity in different organisms. It is essential for
humans. Iodine is also another compound.
Halogen atoms are mostly lipophilic and less water-soluble. Thus, it has been used in
drug components to provide improved penetration through lipid membranes and
tissues. However, halogenated drugs can pile up in adipose tissue.
Polyhalogenated compounds (PHCs) are used in a wide array of manufactured products
and in pest control.
The noble gases (historically also the inert gases; sometimes referred to as aerogens[1])
make up a class of chemical elements with similar properties; under standard
conditions, they are all odorless, colorless, monatomic gases with very low chemical
reactivity. The six naturally occurring noble gases are helium (He), neon (Ne), argon
(Ar), krypton (Kr), xenon (Xe), and the radioactive radon (Rn).
The noble gases were the last group of elements to be discovered. Their properties were
not investigated until the very late 19th and early 20th century, long after Mendeleev
first proposed his periodic table. They are monatomic gases (made of single atoms) and
so unreactive that at first they were called the inert gases, meaning that they would not
react with any other elements. They have very low boiling points and melting points,
and are only present in trace amounts on Earth, except for argon which occupies 1% of
the atmosphere. They all emit visible light when electricity is passed through them.
Their lack of reactivity is due to their electron configurations: their atoms all have full
shells of electrons. Very large amounts of energy would be needed to disrupt these full
shells to make the atoms react. However, in 1962 it was discovered that xenon could
form compounds, and so we now call them noble gases rather than inert gases. A
number of noble gas compounds have been made containing radon, xenon and krypton,
mainly combined with fluorine or oxygen.
The properties of the noble gases can be well explained by modern theories of atomic
structure: Their outer shell of valence electrons is considered to be "full", giving them
little tendency to participate in chemical reactions, and it has been possible to prepare
only a few hundred noble gas compounds. The melting and boiling points for a given
noble gas are close together, differing by less than 10 °C (18 °F); that is, they are
liquids over only a small temperature range.
Like other groups, the members of this family show patterns in its electron
configuration, especially the outermost shells resulting in trends in chemical behavior:
Z
Element
No. of electrons/shell
2
10
18
36
54
86
helium He
2
neon Ne
2, 8
argo Ar
2, 8, 8
krypton Kr 2, 8, 18, 8
xenon Xe
2, 8, 18, 18, 8
radon Rn 2, 8, 18, 32, 18, 8
Chemical properties. An atomic shell diagram with neon core, 2 electrons in the inner
shell and 8 in the outer shell. Neon, like all noble gases, has a full valence shell. Noble
gases have eight electrons in their outermost shell, except in the case of helium, which
has two.
The noble gases are colorless, odorless, tasteless, and nonflammable under standard
conditions. They were once labeled group 0 in the periodic table because it was
believed they had a valence of zero, meaning their atoms cannot combine with those of
other elements to form compounds. However, it was later discovered some do indeed
form compounds, causing this label to fall into disuse.
Uses of noble gases.
In many applications, the noble gases are used to provide an inert atmosphere. Argon is
used in the synthesis of air-sensitive compounds that are sensitive to nitrogen. Solid
argon is also used for the study of very unstable compounds, such as reactive
intermediates, by trapping them in an inert matrix at very low temperatures. Some
noble gases have direct application in medicine. Helium is sometimes used to improve
the ease of breathing of asthma sufferers. Xenon is used as an anesthetic because of its
high solubility in lipids, which makes it more potent than the usual nitrous oxide, and
because it is readily eliminated from the body, resulting in faster recovery. Xenon finds
application in medical imaging of the lungs through hyperpolarized MRI. Radon,
which is highly radioactive and is only available in minute amounts, is used in
radiotherapy. Noble gases, particularly xenon, are predominantly used in ion engines
due to their inertness. Since ion engines are not driven by chemical reactions,
chemically inert fuels are desired to prevent unwanted reaction between the fuel and
anything else on the engine.
Oganesson is too unstable to work with and has no known application other than
research.
10 min
Feedback. Frequently Asked Questions on Halogens
1.Which group elements are called halogens? Elements of group 17 are called
halogens.
2.What elements are called halogens? Fluorine, Chlorine, Bromine, Iodine and
Astatine.
3.Which halogen is radioactive? Astatine is a radioactive element belonging to the
halogens
4.Which halogen is a liquid at room temperature? Bromine is a liquid at room
temperature.
Frequently Asked Questions on Noble gases
1. What are noble gases? Noble gases belong to a special category of elements in the
periodic table that are inert, non-metal, and non-reactive.
2. Where are the noble gases located on the periodic table? The noble gases are located
toward the right of the periodic table in group number VIIIa (new IUPAC) or 18 (CAS)
3. Physical Properties of Noble Gases - very low melting and boiling points.
4. What is the heaviest of the noble gases? Radon is the heaviest of the noble gases.
2 min
III. Homework assignment (Worksheet)
Worksheet
1. An oxide of xenon is found to contain 73.19 % xenon.
(a) Calculate its empirical formula. (Xe = 131; O = 16)
(b) Is this compound more likely to be made of ions or molecules? Explain your answer.
(a)_______________________________________________________________
(b)________________________________________________________________
Answers:
(a) 73.19/131 = 0.5587 Xe. 26.81/16 = 1.676 O. Hence the ratio Xe:O = 1:3; the empirical
formula is XeO3
(b) It is made of molecules. Xenon and oxygen are both non-metals, so they are likely to be
covalently bonded in this compound
2. Name the following compounds:
H2OCO2 SiO2 –
Answers:
H2O - Water
CO2 - Carbon dioxide
SiO2 - Sand
3. Write the formulas for the following compounds:
Sodium chloride –
Simple substance bromine –
Fluorine oxide
Answers:
Sodium chloride – NaCl
Simple substance bromine – Br2
Fluorine oxide – OF2
3. Chemical properties of oxegen:
_____________________________________________________________________________
Answers: Oxygen therefore oxidizes metals to form salts in which the oxygen atoms are formally
present as O2- ions
4. Physical properties of nitrogen:
_____________________________________________________________________________
Answers: It is colourless gas without smell
4. Conclusion
The nonmetals are located on the upper right side of the periodic table. Nonmetals are separated
from metals by a line that cuts diagonally through the region of the periodic table containing
elements with partially filled p orbitals. The halogens and noble gases are nonmetals, but the
nonmetal element group usually consists of the following elements:
hydrogen
carbon
nitrogen
oxygen
phosphorus
sulfur
selenium
The halogen elements are:
fluorine
chlorine
bromine
iodine
astatine
tennessine (possibly, although most scientists think this element will behave as a metalloid)
The noble gas elements are:
helium
neon
argon
krypton
xenon
radon
oganesson - This element is predicted to be a liquid noble "gas", but is still a nonmetal.
Nonmetals have high ionization energies and electronegativities. They are generally poor
conductors of heat and electricity. Solid nonmetals are generally brittle, with little or no metallic
luster. Most nonmetals have the ability to gain electrons easily. Nonmetals display a wide range
of chemical properties and reactivities.