SPM Chemistry Form 4 (Periodic Table Of Elements) Chapter 4 - Part 1 Complete Revision
Summary
TLDRThis video lesson introduces Form 4 Chemistry, focusing on the periodic table of elements. It covers the development of the periodic table, highlighting contributions from scientists such as Antoine Lavoisier, Dmitri Mendeleev, and Henry Moseley. The lesson also explains the arrangement of elements by atomic number, the significance of groups and periods, and how electron configurations determine an element's position in the table. Viewers will learn about the properties of different groups, like alkali metals and halogens, and the relationship between valence electrons and chemical properties.
Takeaways
- đŹ Antoine Lavoisier was the first scientist to classify elements based on common characteristics.
- đ Johann Döbereiner classified elements with similar chemical properties into groups called Triads.
- đ Lothar Meyer discovered that elements with equivalent positions on an atomic mass vs. volume graph share similar chemical properties.
- đ§Ș Dmitri Mendeleev arranged elements by ascending atomic mass and left spaces for undiscovered elements, predicting their properties.
- đ¶ John Newlands identified the periodic repetition of elements' chemical properties every eight elements, known as the Law of Octaves.
- đ Henry Moseley reorganized Mendeleev's table using atomic (proton) number, leading to the modern periodic table.
- 𧟠The modern periodic table is arranged by proton number with 18 groups and 7 periods, categorizing elements by shared properties.
- đ§ Elements in the same group share the same number of valence electrons and display similar chemical properties.
- âïž Metallic properties gradually change from metals to metalloids and non-metals across periods.
- âïž Group and period numbers of an element are determined by its valence electrons and the number of electron shells, respectively.
Q & A
What was Antoine Lavoisier's contribution to the classification of elements?
-Antoine Lavoisier, a French chemist, was the first to classify elements into groups based on their common characteristics between 1743-1794.
What is Johann Döbereiner's Triad theory?
-Johann Döbereiner, a German chemist, classified elements with similar chemical properties into groups called Triads, where the atomic mass of the middle element is roughly the average of the other two elements.
How did Lothar Meyer's work contribute to the periodic table?
-Lothar Meyer, a German chemist, plotted a graph of atomic volume against atomic mass and discovered that elements with similar chemical properties occupied equivalent positions on the curve, leading to the grouping of elements like alkali metals.
What was Dmitri Mendeleev's major advancement in the development of the periodic table?
-Dmitri Mendeleev rearranged all known elements in ascending order of atomic mass and grouped elements with similar chemical properties into vertical columns (groups). He also left spaces for undiscovered elements, predicting their properties based on their positions.
What is Newlands' Law of Octaves, and how did it relate to the periodic table?
-John Newlands, a British chemist, noticed that elements exhibited periodic repetition of chemical properties every eighth element, similar to the octaves in music. This phenomenon was called the Law of Octaves.
What role did Henry Moseley play in the modern periodic table?
-Henry Moseley, a British chemist, discovered the proton number of elements and rearranged Mendeleevâs periodic table by increasing proton number, leading to the modern periodic table.
How are the elements arranged in the modern periodic table?
-In the modern periodic table, elements are arranged in the ascending order of proton number from left to right. The table consists of 18 groups (vertical columns) and 7 periods (horizontal rows).
What is the difference between a group and a period in the periodic table?
-A group is a vertical column where elements have the same number of valence electrons and similar chemical properties, while a period is a horizontal row where all elements have the same number of electron shells.
What is a halogen, and how can its position in the periodic table be identified?
-A halogen is an element in Group 17 of the periodic table, characterized by having seven valence electrons. The group includes elements like fluorine and chlorine.
How is the electron arrangement of an element related to its group and period number?
-The group number of an element is determined by the number of valence electrons, while the period number is determined by the number of shells filled with electrons. For example, an element in Group 15 and Period 3 has five valence electrons and three electron shells.
Outlines
đ Development of the Periodic Table of Elements
In this section, we learn about the early classification and development of the periodic table. Starting with Antoine Lavoisier (1743-1794), who grouped elements based on common characteristics, we then move to Johan Döbereiner (1780-1849), who introduced the concept of 'Triads'âgroups of three elements with similar properties and relative atomic masses. German chemist Lothar Meyer (1830-1895) plotted atomic volume against atomic mass, observing repeating chemical properties. Dmitri Mendeleev (1834-1907) arranged elements by increasing atomic mass, predicting properties of undiscovered elements. John Newlands (1837-1898) noted a periodic repetition of chemical properties and coined the 'Law of Octaves.' Finally, Henry Moseley (1887-1915) determined proton numbers and arranged the table accordingly, leading to the modern periodic table we use today.
đ§Ș Arrangement of Elements in the Modern Periodic Table
This section describes the organization of the modern periodic table, which arranges 118 elements by increasing proton number. The vertical columns are called 'groups,' and there are 18 in total. Groups include notable categories like Group 1 (Alkali Metals), Group 2 (Alkaline Earth Metals), Groups 3-12 (Transition Metals), Group 17 (Halogens), and Group 18 (Noble Gases). Elements in the same group share similar chemical properties and have the same number of valence electrons. The horizontal rows, called 'periods,' represent elements with the same number of electron shells. Metallic properties decrease from left to right across a period. The section also explains how valence electrons determine group numbers, with examples illustrating the electron arrangements of certain elements.
Mindmap
Keywords
đĄPeriodic Table of Elements
đĄAntoine Lavoisier
đĄTriads
đĄDmitri Mendeleev
đĄLaw of Octaves
đĄHenry Moseley
đĄProton Number
đĄGroup
đĄPeriod
đĄValence Electrons
Highlights
Introduction to Chemistry Form 4, Chapter 4 - Periodic Table of Elements.
Development of the periodic table started with Antoine Lavoisier (1743-1794), who grouped elements based on common characteristics.
Joanne W. Döbereiner (1780-1849) introduced the concept of triads, grouping elements with similar chemical properties.
Lothar Meyer (1830-1895) discovered that elements with similar chemical properties repeated periodically when arranged by atomic mass.
Dimitri Mendeleev (1834-1907) organized elements in increasing atomic mass, left spaces for undiscovered elements, and predicted their properties.
John Newlands (1837-1898) proposed the Law of Octaves, noting the periodic repetition of chemical properties every eight elements.
Henry Moseley (1887-1915) rearranged elements by proton number, forming the foundation of the modern periodic table.
The modern periodic table consists of 118 elements arranged in increasing proton number.
Vertical columns in the periodic table are called groups, with 18 groups in total.
Group 1 elements are alkali metals, and Group 17 elements are halogens, known for their seven valence electrons.
Horizontal rows in the periodic table are called periods, with each period representing elements with the same number of electron shells.
Period 6 and Period 7 consist of 32 elements, known as the lanthanide and actinide series respectively.
The arrangement of elements in the periodic table reflects a transition from metals on the left to non-metals on the right.
The relationship between electron arrangement and the elementâs position in the periodic table is key in determining chemical behavior.
Helium, despite having two valence electrons, is placed in Group 18 due to its chemical properties aligning with inert gases.
Transcripts
foreign
teacher Daisy now let's learn form 4
Chemistry chapter 4 part 1 periodic
table of elements in this part you will
learn 4.1 the development of the
periodic table of elements 4.2 the
arrangement of elements in the periodic
table of elements
4.1 the development of the periodic
table of elements
1743-1794 Antoine Lavoisier a French
chemist was the first scientist started
the classification of elements into
groups based on their common
characteristics
teen
80-1849 Joanne w doberiner a German
chemist classified elements with similar
chemical properties into groups named
Triads
each Triad consists of three elements
only
the relative atomic mass of the middle
element in each Triad is roughly similar
with the average of the relative atomic
mass of the other two elements in the
Triad
1830-1895 low tar mire a German chemist
plotted graph of atomic volume against
atomic mass for all discovered elements
he found the same chemical properties
repeat on elements occupied equivalent
position on the Curve
alkali metals lithium sodium potassium
rubidium occupied equivalent position
Peak on the curve so classified into a
group
1834-1907 Dimitri Mendeleev a chemistry
Russian Professor rearranged all
discovered elements in the ascending
order of relative atomic mass
classified the elements with similar
chemical properties into the same
vertical column named group
left empty spaces for undiscovered
elements
using the position of an Undiscovered
elements in the periodic table of
element to predict its properties
1837-1898 John Newlands a British
chemist arranged 56 elements in the
increasing order of relative atomic mass
noted the periodic repetition of
chemical properties of element eight
places further on
he named this phenomenon as law of
octave as this is similar to the octaves
of music
octaves Newlands law 1865
1887-1915 Henry Mosley a British chemist
he found the proton number of an element
during the experiment to study the
frequency of x-rays released by
different elements
each element has its specific proton
number
rearrange the elements in the Mandela's
periodic table in the ascending order of
proton number
left empty spaces for undiscovered
elements the periodic table of elements
proposed by Mosley was then developed
into the modern periodic table of
elements we use today
December 1 2018 modern periodic table of
elements latest from International Union
of pure and applied chemistry iapac
4.2 the arrangement of elements in the
periodic table of elements
all 118 elements are arranged in the
ascending order of proton number from
left to right
the vertical column is called group
there are 18 groups in the periodic
table of elements
main elements groups group and specific
name Group 1 Alkali metal group 2
alkaline earth metal group 3 to 12
transition elements or transition metals
Group 17 halogen group 18 inert gases or
noble gases note that hydrogen is not an
Alkali metal even though it is placed
above lithium and hydrogen atom has one
valence electron
elements in the same group have same
number of valence electrons
elements that show similar chemical
properties are arranged in the same
group vertical column
example Group 1 elements have valence
electron of one
electron Arrangement lithium Li 2.1
sodium and
a2.8.1 potassium K
2.8.8.1 rubidium air Bay
2.8.18.8.1 the physical properties such
as melting point boiling point density
and color changed gradually down the
group
horizontal row is known as period
all elements in a period have same
number of shells filled with electrons
there are seven periods in the periodic
table of elements
short period period 1 consists of two
elements
Period 2 and 3 consist of eight elements
period 4 and 5 consist of 18 elements
long period period 6 consists of 32
elements and it is called lanthanide
series
period 7 consists of 32 elements and it
is called actinide series
example period 3 elements all have three
shells filled with electrons
metallic elements are located at the
left while non-metallic elements are
located at the right of the periodic
table
the metallic properties of elements
change gradually from metal to metalloid
semi-metal and then non-metal when
moving across the period
example figure shows the electron
arrangement for X Y and Z atoms which
element is a halogen
solution halogen is the specific name
assigned to group 17 all halogens have
seven valence electrons why atom has
seven valence electrons
the relationship between electron
arrangement of the first 20 elements and
their positions in the periodic table of
elements the group number of an element
is determined by the number of valence
electrons in an atom for the elements
with one or two valence electrons group
number equals number of valence
electrons for the elements with 3 to 8
valence electrons group number equals
number of valence electrons plus 10
helium with two valence electron placed
in group 18 is an exception
this is because helium shows similar
nerve chemical properties as other inert
gases in group 18.
the relationship between the electron
Arrangement and the period number of an
atom period number equals number of
shells filled with electrons
example element p is placed in group 15
and period 3 the periodic table of
elements what is the electron
arrangement for atom p
solution atom P has five valence
electrons because it is placed in group
15.
atom P has three shells filled with
electrons because it is placed in Period
3.
electron arrangement of atom P equals
2.8.5
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