Elements lesson
-
Upload
bassantnour -
Category
Education
-
view
317 -
download
0
Transcript of Elements lesson
![Page 1: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/1.jpg)
Atomic Theory
![Page 2: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/2.jpg)
Greek Philosophers• Aristotle
4Elements of matter
-Earth -Fire -Air -Water
![Page 3: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/3.jpg)
Matter is made of atoms (cannot be further divided), the word atom comes from the Greek word “atomos” which means indivisible.
Democritus
![Page 4: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/4.jpg)
• Atoms were tiny particles that could not be divided• John Dalton proposed that an atom is a sphere of
matter that is the same throughout and can’t be seen by human eyes
• Marble Model
![Page 5: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/5.jpg)
• Came up with the idea of the electron negatively charged particle• Thomson discovered that all atoms contain electrons, which are tiny,
negatively charged particles. Thomson proposed that an atom is a sphere of positive charge. The electrons are mixed uniformly in the sphere.
• Cookie Model
![Page 6: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/6.jpg)
Ernest Rutherford• He hypothesized that almost all the mass and all the
positive charge of an atom is concentrated in an extremely tiny nucleus at the center of the atom.
![Page 7: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/7.jpg)
• Thought electrons traveled in fixed paths around the nucleus called energy levels.
![Page 8: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/8.jpg)
Atomic Structure• Arrangement and number of sub-atomic particles
•Protons•Neutrons•Electrons
![Page 9: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/9.jpg)
• Center or core of an atom• Contains 99.9% of the weight of an
atom• Contains protons and neutrons
![Page 10: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/10.jpg)
• Positively Charged Sub-atomic particles• Found in the nucleus• All protons are a like
![Page 11: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/11.jpg)
• Neutrally charged (no charge) sub-atomic particle• Found in nucleus
![Page 12: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/12.jpg)
• They are the negatively charged particles orbiting the nucleus.
• It is much smaller than the protons and the neutrons .
![Page 13: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/13.jpg)
What is the net charge of the atom ?
• The atom is formed of positively charged proton in the nucleus and negatively charged electrons in the energy level ,but they are equal to each other in number ,making the net charge of the atom “neutral”.
No of positive protons = No of negative electrons
![Page 14: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/14.jpg)
• They are charged atoms• Number of positive protons = Number of negative electrons.
Positive ion
Negative ion
![Page 15: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/15.jpg)
If the atom lost an electron ,therefore the number of positive protons are more than the negative electrons making the atom positively
charged
Positive Ion
![Page 16: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/16.jpg)
If the atom gained an electron ,therefore the number of negative electrons
are more than the positive protons making the atom negatively charged
Negative Ion
![Page 17: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/17.jpg)
• Atomic number is the number of Protons in an atom
• All atoms of a particular element have the SAME number of protons (All Carbon atoms have 6 protons)
• In a neutral atom,
The atomic number =The number of electrons
![Page 18: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/18.jpg)
• Also called atomic weight or Mass Number• Sum weight of protons and neutrons in an atom
![Page 19: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/19.jpg)
Calculate the mass number of each of the following atoms
![Page 20: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/20.jpg)
O 8
16
Atomic number
Mass number
Symbol
OxygenName
Atomic number= Number of protons= Number of electrons
Mass number= Number of protons + Number of neutrons
![Page 21: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/21.jpg)
Calculating Neutrons:• Mass number = protons + neutrons
so…..• Neutrons = mass number – protons
What is the number of neutrons of the following atom ?
A21
45
![Page 22: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/22.jpg)
• In 1869 Dimitri Mendeleev was working on a way to classify elements.
• At the time, more than 60 elements had been discovered.
• And he arranged the elements according to their atomic mass
Developing a Periodic Table
![Page 23: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/23.jpg)
100 table The periodic table is a chart of the
elements arranged according to their atomic number in rows and columns according to their
physical and chemical properties.
![Page 24: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/24.jpg)
![Page 25: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/25.jpg)
![Page 26: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/26.jpg)
Symbol
![Page 27: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/27.jpg)
•The periodic table is a chart of the elements arranged into rows and columns according to their physical and chemical properties.
• It can be used to determine the relationships among the elements.
What is the periodic table?
![Page 28: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/28.jpg)
Groups and Periods - Columns in the periodic table represents “groups”- There are 18 groups in the periodic table.- Elements of the same the same group have the same
chemical properties as the all have the same number of electron/s in the outer most energy levels.
![Page 29: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/29.jpg)
- Rows in the periodic table represent “periods”.- There are 7 periods in the periodic table .- Elements of the same period have the same number
of energy levels
![Page 30: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/30.jpg)
The Periodic Table of Elements
![Page 31: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/31.jpg)
Periodic Table
A great deal of information about an element can be gathered from its position on the period table.
Understanding the organization and plan of the periodic table will help you obtain basic information about each of the 118 known elements.
![Page 32: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/32.jpg)
Mass Number
Atomic Mass (Mass Number) is the number …………….
__________Atom p+ n0 e- Mass #
Oxygen - 8
- 33 42
- 31 15
___ ___ ______
______ ___ ___ ___
______ ___ ______
![Page 33: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/33.jpg)
Recall - How are P, N, e- related?• atomic number = # protons
• # protons = …………….
• # protons + # neutrons = atomic mass# neutrons = ……………. …………….
![Page 34: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/34.jpg)
• How many protons, neutrons and electrons are found in an atom of Cs?
• _____________• …………….
• ……………. • Therefore, # Neutrons = …………….
_____________ _____________
55Cs
133
Example 1
![Page 35: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/35.jpg)
NaSodium
23
11_________________________________
![Page 36: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/36.jpg)
Example 2 If an element :Magnesium
a) number of protons
b) number of neutrons
c) number of electrons
d) complete symbol
=_____________
= _____________
= _____________
_____________
![Page 37: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/37.jpg)
ATOM
The smallest particle of an element with the same properties of the element.
![Page 38: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/38.jpg)
MOLECULE
The smallest part of a substance made from more than one atom that binds together.
![Page 39: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/39.jpg)
Let’s Build SomeMolecules
![Page 40: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/40.jpg)
Let's start with a couple of Molecules• Hydrogen Gas H2
H H
• Oxygen Gas O2
O O
![Page 41: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/41.jpg)
• Ammonia Gas NH3
H H
HN
• Water H2O
HH
O
![Page 42: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/42.jpg)
Elements Substance that contains only one kind
of atom
![Page 43: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/43.jpg)
Compounds-Are substances made of atoms of two or more elements
that are chemically combined.-The chemical formula of a compound shows the elements
that are in it
-Example:SiO₂ (sand): It is formed of 1 Silicon atom 2 oxygen atoms
![Page 44: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/44.jpg)
-Compounds don’t have the same properties of the elements forming them
Example:The ordinary table salt is a compound called NaClIt is formed of : 1 atom of Sodium and 1 atom of chlorine Where “Sodium” is a metal
![Page 45: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/45.jpg)
• And “Chlorine” is a gas
But when they combine together they give a product of different properties which is the table salt
![Page 46: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/46.jpg)
How compounds are formed ?-Compounds hold together because atoms bond or
attach to one another
![Page 47: Elements lesson](https://reader035.fdocuments.us/reader035/viewer/2022062522/5889505b1a28abde5a8b71db/html5/thumbnails/47.jpg)
How atoms can attach or bond with each other?
They either
Share electrons
Gain Or
lose electrons