Download - Atomic Structure
![Page 1: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/1.jpg)
Atomic Structure
![Page 2: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/2.jpg)
The Structure of the Atom
Atoms are basic building blocks of matter, and cannot be chemically subdivided by ordinary means.
The Atom
![Page 3: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/3.jpg)
in 1808 John Dalton (an English scientist) states a theory about the nature of the elements known as Dalton’s atomic theory , the main ideas of this theory can be stated as follows:
![Page 4: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/4.jpg)
All atoms of a given element are identical.
Elements are made of a tiny particle called an atom.
The atoms of a given element are different from those of any other element.
![Page 5: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/5.jpg)
Atoms of one element can combine with atoms of other elements to form compounds.
In chemical reactions atoms are neither created nor destroyed they simply change the way they are grouped together.
![Page 6: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/6.jpg)
Later on Thomson & Rutherformed worked on the structure of the atom & they discovered that the atom is
consist of a tiny nucleus ( about 10-13 cm in diameter) and electrons that move around the nucleus . The nucleus contains protons which have a positive charge equal in magnitude to the electron's negative charge , and neutrons , which have almost the same mass as a proton but no charge.
![Page 7: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/7.jpg)
Atoms are composed of three type of particles:
Protons
Neutrons
Electron
![Page 8: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/8.jpg)
The mass & charge of the electron, proton & neutron are given below:
particleparticleRelative Relative massmass
Relative Relative chargecharge
electronelectron 11- - 11
protonproton 18361836+ + 11
neutronneutron 18391839No chargeNo charge
![Page 9: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/9.jpg)
Modern atomic theory:
In 1911 Niels Bohr construct a model of the hydrogen atom with quantized energy levels ,
Bohr picture the electrons moving in circular orbits (like planet orbiting the sun) , corresponding to the various allowed energy levels. He suggested that the electron could jump to different orbit by absorbing or emitting energy.
![Page 10: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/10.jpg)
Bohr’s atomic orbital:
• Is a specific path on which the electrons travel about the nucleus.
+
--
-
![Page 11: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/11.jpg)
Although Bohr's model opened the way for the later theories it is
important to realize that electrons do not move around the nucleus in circular orbits like the planet orbiting the sun.
![Page 12: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/12.jpg)
Later on Schrodinger found that it is not precisely to describe the
electrons path , he could only predict the probability of finding the electron at a given point in space around the nucleus .
![Page 13: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/13.jpg)
The probability map, or orbital that describes the hydrogen electron in it's lowest possible energy state . The more intense the color of a
given dot the more likely it is that the electron will be found at that point.
In its ground state the hydrogen electron has a probability map
![Page 14: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/14.jpg)
![Page 15: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/15.jpg)
Shrodinger showed that the orbitals of electrons are regions of
electron density with the location and routs of electrons described as probabilities.
![Page 16: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/16.jpg)
Atoms with the same number of
protons but different number of
neutrons. In nature elements are
usually found as a mixture of
isotopes.
Isotopes:
![Page 17: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/17.jpg)
Hydrogen 1 (hydrogen)
1 proton, 0 neutronsMass number = 1
Hydrogen 2 (deuterium)
1 proton, 1 neutronMass number = 2
Hydrogen 3 (tritium)
2 neutronsMass number = 3
![Page 18: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/18.jpg)
Example
Three isotopes of elemental carbon are C6
12 , C613, C6
14 . Determine the number of each of the three types sub atomic particles in each of these carbon atoms.
![Page 19: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/19.jpg)
Mass number: The sum of the number of neutrons & number of protons in a given nucleus.
Atomic number: The number of protons in the nucleus.
![Page 20: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/20.jpg)
Electrons may be added to a certain atoms to form a negatively charged particle (anion). These charged particles whether positive or negative are called ions.
Ions:
Under certain circumstances it is possible to remove electrons from a neutral atom leaving a positively
charged particle (cation) .
![Page 21: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/21.jpg)
Quantum numbers:
The various orbitals available to an atom are
described by four quantum numbers, which can
take certain values to create differently sized and
shaped orbital of various energies:
Atomic Orbital
![Page 22: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/22.jpg)
describes the:
Shells:(an electron shell is collection of orbital's)
Size of orbital
Numbered 1, 2, 3, 4, 5, etc
are often lettered (K, L, M, etc.).
The principal quantum number (n)
![Page 23: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/23.jpg)
describes the:
Subshells : are groups of orbitals with in an electron
Shape of orbital (number of lobes).
Given letters s, p, d, f, g, h, i, etc.
The values of ( l ) run from 0 to n − 1
The subsidiary quantum number (l)
![Page 24: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/24.jpg)
describes:
Orientation of the orbitals in space.
Named after the directions they point in (x, y, z, etc.)
Can also be given numbers ranging from 0, ±1, ±2, ±3 … ±l.
The magnetic quantum number (m)
![Page 25: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/25.jpg)
The spin quantum number (s).
describes:
spin of an electron on its own axis
May have the values +½ or -½.
Two electrons in the same orbital have paired
(opposite) spins
![Page 26: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/26.jpg)
The Quantum Numbers
namesymbolvalues
Principal Quantum Numbernany integer from 1 to infinity
Subsidiary Quantum Numberlany integer from 0 to n-1
Magnetic Quantum Numbermany integer from - l to + l
Spin Quantum Numbers -/+1/2
![Page 27: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/27.jpg)
L-valueorbital type
No. of orbitalsMax no. of electrons
0s12
1p36
2d510
3f714
![Page 28: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/28.jpg)
Using symbols, the valid quantum states can be listed in the following manner: 1s
2s 2p
3s 3p 3d
4s 4p 4d 4f
5s 5p 5d 5f 5g
6s 6p 6d 6f 6g 7h
7s 7p 7d 7f 7g 7h 8i
![Page 29: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/29.jpg)
Atomic Orbitals
The S Orbital
The simplest orbital in the atom is the 1s orbital.
The 1s orbital is simply a sphere of electron density.
There is only one s orbital per shell
The s orbital can hold two electrons have different
spin quantum numbers l = 0
m = 0
S = +1/2 , -1/2
![Page 30: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/30.jpg)
1s Shell
![Page 31: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/31.jpg)
The P Orbitals
Starting from the 2nd shell, there is a set of p
orbitals
There are 3 choices for the magnetic quantum
number, which indicates 3 differently orientated
p orbitals px, py, and pz
each orbital can accommodate two electrons,
giving a total capacity of 6 electrons.
p orbitals are very often involved in bonding
![Page 32: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/32.jpg)
l = 1
m = -1, 0, 1
S = +1/2 , -1/2
![Page 33: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/33.jpg)
2 px
![Page 34: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/34.jpg)
2py
![Page 35: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/35.jpg)
2pz
![Page 36: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/36.jpg)
px py pz
![Page 37: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/37.jpg)
Electronic configuration of elements
Rules for electronic configuration:
The Pauli Exclusion principle:
Only two electrons with opposite spin can occupy an atomic orbital (or no two electrons have the same (4) quantum numbers n, l, m and s)
1s
![Page 38: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/38.jpg)
Hund's Rule:
Electrons prefer parallel spins in separate orbitals of subshells
The Aufbau Principle:
Explains the order in which the electrons fill the various orbitals in an atom.
Filling begins with the orbitals in the lowest- energy shells and continues through the higher-energy shells
![Page 39: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/39.jpg)
The energy relationships among the first three levels of orbitals;
![Page 40: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/40.jpg)
1s 2s 3s 4s 5s 6s 7s
2p 3p 4p 5p 6p 7p
3d 4d 5d 6d
![Page 41: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/41.jpg)
Example :
Write a complete electronic configuration for the noble gases; He, Ne, Ar, Kr, Xe,
Solution:
This can be written in the normal configuration representation As shown below:
![Page 42: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/42.jpg)
He2 1s2
Ne10 1s2 2s2 2p6
Ar18 1s2 2s2 2p6 3s2 3p6
Kr36 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6
Xe54 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6
![Page 43: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/43.jpg)
Or can be shown in the box representation as shown below :
He2
1s
Ne10
Ar18
1s
1s
2s
2s
2p
2p 3s 3p
![Page 44: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/44.jpg)
Example :
Write a complete electronic configuration for each of the eight elements; from Na to Ar:
Na11 1s2 2s2 2p6 3s1 or [Ne] 3s1
Mg 12 1s2 2s2 2p6 3s2 [Ne] 3s2
Al13 1s2 2s2 2p6 3s2 3p1 [Ne]3s2 3p1
Si14 1s2 2s2 2p6 3s2 3p2 [Ne] 3s2 3p2
P15 1s2 2s2 2p6 3s2 3p3 [Ne] 3s2 3p3
S16 1s2 2s2 2p6 3s2 3p4 [Ne] 3s2 3p4
Cl17 1s2 2s2 2p6 3s2 3p5 [Ne] 3s2 3p5
Ar18 1s2 2s2 2p6 3s2 3p6 [Ne] 3s2 3p6
![Page 45: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/45.jpg)
Special electronic configuration: The pairing of electrons raise the orbital energy
slightly.
Half-filled and full-filled subshell low the energy.
For example the electronic configuration of Cr and
Cu
Cr24
1s 2s 2p 3s 3p 4s 3d
Cu29
1s 2s 3s 4s 3d2p 3p
![Page 46: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/46.jpg)
1 -which of the following pair of atoms contain the same
number of neutrons?
A- C614 & C6
12
B- F919 & Ne10
22
C- S1632 &Al13
29
Tutorial (A)
![Page 47: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/47.jpg)
2 -Which of the following particles does not contain
the same number of electrons as fluoride ion (F -)
A- Ne
B- Li +
C- Na +
![Page 48: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/48.jpg)
3 -the electronic configuration of helium atom ,boron
atom , carbon atom & element X are given below.
Which one could be the electronic configuration of
element X?A- 1s2 2s22P1
B- 1s2
C- 1s2 2s1
D- 1s2 2s2 2p2
![Page 49: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/49.jpg)
4- atoms which have the same electronic configuration are said to be isoelectronic which of the following is not isoelectronic with O2-?
A- N 3-
B- Al 3+
C- Na +
D- Na
![Page 50: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/50.jpg)
5 -the magnetic quantum number (m) gives
A- the sub shells
B- the orbitals
C- the spin of the electron .
![Page 51: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/51.jpg)
Tutorial (B)
1- an orbital can take a maximum of…………..electrons.
2- an( s ) sub level can take a maximum of……electrons.
3- the (p) sub level can take a maximum of…….electrons.
4- how many electrons can fit in to a set of (5d) orbitals?
5- what is the maximum numbers of electrons in levels,
2, 3, 4 ?
![Page 52: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/52.jpg)
6 -which of the following orbitals could not be exist?
1s,1p,1d,2s,2p,2d,3p,3d,3f,4s,4f.
7- write the four quantum numbers for energy
level(4)?
8- For the H-like atom, which subshell has the highest
energy level?
4f, 3d, 2p, 1s
![Page 53: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/53.jpg)
9- How many electrons are required to fill all the
following subshells?
1s 2s 2p 3s 3p 4s 3d 4p
10- Which of the following two electronic configuration
is more stable?
a- [Ar]4s1 3d5
b- [Ar]4s2 3d4
![Page 54: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/54.jpg)
11- Which of the following two electronic configurations is more stable?
a [Ar]4s2 3d9
b [Ar]4s1 3d10
12- Choose the electronic configuration for palladium, Pd (Z = 46).
a- [Kr]5s1 4d7
b- [Kr]5s1 4d8
c- [Kr]5s0 4d10
d- [Kr]5s1 4d10
![Page 55: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/55.jpg)
By the late 1800's many elements had already been discovered.
The scientist Dmitri Mendeleev, a Russian chemist, proposed an arrangement of known elements based on their atomic mass
The modern arrangement of the elements is known as the Periodic Table of Elements and is arranged according to the atomic number of elements.
The Periodic Table of Elements
![Page 56: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/56.jpg)
Periodic law:
The modern periodic law states that ; when elements
are arranged by atomic number; their physical and
chemical properties vary periodically .
![Page 57: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/57.jpg)
The periodic table displays the elements in rows (periods ) and columns in order of increasing atomic number.
Elements that have similar chemical properties fall into vertical columns called groups or families
Most of the elements are metals and located on the left hand side of the periodic table
The nonmetals appear on the right hand side of the periodic table
![Page 58: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/58.jpg)
From the periodic table we can know many information
directly like symbol, atomic number, atomic mass & you
can also know whether the element is metal, non metal
or metalloid.
Today's periodic table consist of seven horizontal rows
called periods & a number of vertical columns called
groups.
![Page 59: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/59.jpg)
All elements in each group have the same number of
electrons in their outer most shells so the behave similarly.
We have two types of groups:
Group (A): ( representative or main elements)
Group (B):( transition elements)
![Page 60: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/60.jpg)
![Page 61: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/61.jpg)
Metals : are found on the left-hand and at the centre of the periodic table
Non metals: are relatively few they are in the upper-right hand corner the table
Metalloids : those are few elements exhibit both metallic and nonmetallic behavior (also known as semimetals)
![Page 62: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/62.jpg)
Group 1A metals (Li, Na, K, Rb, Cs, and Fr) are called the alkali metals , and they are the most reactive metals in the periodic table.
Group 2A metals (Be, Mg, Ca, and Ra) are called the alkaline earth metals.
![Page 63: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/63.jpg)
Group 1B (Cu, Ag and Au) are called the coinage metals
Although these elements have outer electronic configuration similar to those of the alkali metals and the alkaline earth metal the are much less reactive
Group 7A (F, Cl, Br and I) are called halogens and they are the most reactive nonmetals in the periodic table
Group 8A (He, Ne, Ar, Kr, Xe, and Rn) are called the rare or noble gases,
these gases are characteristic by their completely filled shells, for this reason they are chemically inert.
![Page 64: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/64.jpg)
Physical properties of elements
Ionization Energy (I):Is the energy required to remove an electron from an isolated atom in its ground state.X(g)
![Page 65: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/65.jpg)
![Page 66: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/66.jpg)
![Page 67: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/67.jpg)
Chemical Bonds:
In nature elements or compounds exist due to combination of similar or different atoms
Atoms and molecules are electrically neutral, according to this fact in atom combination each tries to exhibit 8 electrons on the outer most shell that by loosing, gaining or sharing electrons.
![Page 68: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/68.jpg)
Metals: have three or less electrons e.g. Na, Ca, Fe
Nonmetals: Have five or more electrons e.g. H, N, S
Carbon atom: have four electrons in the outer most shell liable to loose them or to gain more electrons
![Page 69: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/69.jpg)
The Bonds By which atoms can combine are :
Ionic Bond
Covalent Bond
Co-ordinate Bond
![Page 70: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/70.jpg)
Ionic BondIonic Bond
This is Characteristic of metallic and non metallic
combination forming a neutral molecule.
It is achieved via two steps:
Ionization of atoms
Formation of the molecule
![Page 71: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/71.jpg)
Ionization of atoms:
Na Na+
+ e-
Ca Ca+ +
+ 2e- Cations
Cl Cl-
+ e-
S + 2e S- - Anions
![Page 72: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/72.jpg)
Formation of the molecule
In formation of molecules, loss or gain of electron
occurs at the same time.
![Page 73: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/73.jpg)
e.g. Formation of NaCl:
Na Na+
+ e -
Chlorine atom attacks this electron to its outermost
shell and become an anion.
Cl Cl+ e- -
![Page 74: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/74.jpg)
Thus two ions of different charges of equal number are
formed, attraction between them taken place, leading
to the formation of the neutral molecule NaCl.
Na+
Cl-
+ NaCl
NaCl is said to be ionic compound
![Page 75: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/75.jpg)
Example:
Formation of CaCl2 ;
Ca Ca+ +
+ 2e-
Cl Cl-
+ e-
Ca+ +
Cl-
Cl-
+CaCl2
![Page 76: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/76.jpg)
Covalent BondCovalent Bond
The covalent bond is the chemical bond in which
two or more non metal atoms share electrons Both atoms are unable to loose or gain electrons
By sharing electrons both atoms reach octet state
![Page 77: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/77.jpg)
e.g. Fluorine atom has 7 electrons in its outermost
shell. It needs one electron to reach its octet.
To achieve this F atom shares an electron
belonging to another F atom
By this F2 molecule is formed
![Page 78: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/78.jpg)
F + F F F
F F F2
Single Covalent Bond
![Page 79: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/79.jpg)
Examples:
Water molecule:
OH H ++ OH H
OH H H2O
Single Covalent Bond
![Page 80: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/80.jpg)
Ammonia molecule:
N + 3H N
H
HH
NH H
H
NH3
Single Covalent Bond
![Page 81: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/81.jpg)
Oxygen molecule:
O O+ O O
O O O2
Double Covalent Bond
![Page 82: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/82.jpg)
Nitrogen molecule:
N N+ N N
N N N2
Triple Covalent Bond
![Page 83: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/83.jpg)
Co-ordinate BondCo-ordinate Bond
Coordinate covalent bonding is a special type of
bonding, in which the bonding electrons originate
solely from another atom.
![Page 84: Atomic Structure](https://reader034.vdocuments.us/reader034/viewer/2022042510/54801764b4af9f735e8b46f5/html5/thumbnails/84.jpg)
e.g. SO2 molecule:
O + O + S SO O
O OS SO2
Co-ordinate Covalent Bond