TEACHER DIALOGUE AND STUDENTS
Teacher : Good morning students.
Students : Good morning miss.
Teacher : How are you today?
Students : I am fine, miss. How about you?
Teacher : I am great.
Teacher : Hi
Sarah, are you feeling better now? You were sick yesterday, right?
Sarah :
I
am getting much better miss.
Teacher :
Good. Okay, we will start our lesson. Sunday yesterday we've been talking about atoms. Now we will discuss about
Classes and periods in the periodic elements periodic system. Before we start,
who still remember the notion of atoms and elements?
Andi :
Atoms are the smallest unit of matter consisting of a nucleus, which usually
contains protons (charge +) and neutrons (neutrons), and skins that contain
negative charges of electrons. There is also a mention that the atom is the
elemental constituent particles.
Amy :
Elements are A group of atoms that have the same number of protons at their
core. This number is referred to as the atomic number of elements. The element
is also defined as a single substance that can no longer be divided into
smaller parts.
Teacher :
Nice Andi, Amy. Now we will begin to discuss about the arrangement of elements
in the periodic table. All carry the periodic system I ordered,right ?
Students : Yes miss.
Teacher :
The periodic table of elements consists of chemical elements that have been
discovered or made; They are arranged, in the order of atomic numbers in seven
horizontal periods, with lanthanides (lanthanum, 57 to lutetium, 71) and
actinoids (actinium, 89 to lawrencium, 103). Who knows the understanding of the class?
Collins :
Period is an element located on the same line on the periodic system
Teacher : Good Collins, Who else wants to
add?
Amy : Periods are horizontal lanes in the periodic system.
Teacher :
All is true, so the period is the horizontal lanes in the periodic (repetition)
system. This means the period will go down in its order, according to its
periodic number. The number of elements in the modern periodic system is not
the same as each order but increases. In modern periodic systems we have 7
periods. We can see the table peride or you can see below for the number of
elements each period.
Period
1 = 2 elements
Period
2 = 8 elements
Period
3 = 8 elements
Period
4 = 18 elements
Period
5 = 18 elements
Period
6 = 32 elements
Period
7 = 32 elements
Now, who knows what that class is?
Karine : Class is an element that resides
in the same column
Teacher :
That’s good karine. Groups are vertical columns in the periodic system. That
is, the periodic system is distinguished by horizontal on the periodic table.
Take a look at the periodic table. Who can name the class
A?
Githa : For Group A some have names,
namely;
-
Group IA: Alkali metal (except hydrogen)
-
Group IIA; Metal Alkali Soil
-
Group VIIA: Halogen
-
Group VIIIA: Gas Noble
Cici : Group IIXB has 3 groups. Transitional Group In
In
addition there is a class in the Transitional Group that is the inner
transition group.
There are two transitional groups, among
others, Lanthanides and Actinides.
Teacher :
What your friend is all true, we can see it directly on the periodic table. To
better understand, I will divide the group into 4 groups that will discuss
about the elements contained in the group that was mentioned.
Groups are divided by absence.
Group 1 : Group IA: Alkali metal (except
hydrogen)
Group 2: Group IIA; Metal Alkali Soil
Group 3: Group VIIA: Halogen
Group 4: Group VIIIA: Gas Noble
Next week each group forward presents
its group material.
I hope you guys can work together well.
Okay? Any question?
Students : No miss.
Teacher : Well, so many of our meetings
today. Good afternoon.
Students : Good afternoon,miss.
BalasHapusIn addition to a scientific approach there is also a problem-based approach. Can both methods be used simultaneously?
@hudiaumamifaisal
Of course it can be because we are studying with the method of assessment for the students, so in this case the problem is the scientific approach.
Hapuswhy in the periodic table there is a so called main group ?
BalasHapusGolongan unsur pada sistem periodik unsur modern disusun berdasarkan jumlah elektron valensi (elektron yang terletak pada kulit terluar). Unsur dalam satu golongan mempunyai sifat yang cenderung sama dan ditempatkan dalam arah vertikal (kolom).
HapusPada sistem periodik unsur modern, golongan dibagi menjadi 18 berdasarkan aturan IUPAC. Berdasarkan aturan Amerika, sistem periodik unsur modern dibagi dua golongan yaitu golongan A dan B. Jadi, golongan unsur dari kiri ke kanan ialah IA, IIA, 11113, IVB, VB, VIB, VIIB, VIIIB, IB, 1113, IIIA, IVA, VA, VIA, VIIA, dan VIIIA. Umumnya, digunakan pembagian golongan menjadi A dan B.
What about atomic radius, ionisation energy and electron affinity in period and class?
BalasHapusThe radius of the atom
HapusThe radius of the atom is the distance of the outer elaktron to the atomic nucleus and shows the size of an atom. The radius of the atoms is difficult to measure so that the measurements of the radius of the atom are done by measuring the distance between the two nuclei that are bonded to each other.
In a class, the radius of the atoms increasingly upward tends to decrease. This happens because the more up, the smaller the electron shell. In a period, the right to the radius of the atom tends to be smaller. This happens because the more to the right the number of protons and the number of electrons more and more, while the number of outer shells filled elekteron remain the same so that the pull of the core against the outer electrons getting stronger.
2. Energy ionization
If in an atom there is one electron outside the subcellate that mantab, these electrons tend to easily escape to have a configuration such as noble gases. However, to release electrons from an atom requires energy. The energy required to release electrons from an atom is called ionization energy. In a period of more and more electrons and protons pulling force of the outer electrons with the larger nuclei (small radius) As a result, the electrons are difficult to escape so that the energy to release the electrons is greater. This means a large ionisation energy.
If the number of electrons is small, the pull force of electrons with the nucleus is smaller (the fingers are large). As a result, the energy to release the relatively small outer electrons means a small ionisation energy.
Elemental elements: the ionization energies are getting smaller downward, because the outer electrons are far away from the nucleus (the nucleus pull force is weaker), so that the outer electrons are more easily removed.
The elements are as follows: ionisai energies are generally increasingly to the right increasingly larger, as the right to the core pull force is stronger.
Exceptions:
The elements of Group II A have greater ionization energies than the class III A, and the Group I ionisation energies are larger than the group VI of A.
3. Keelektronegatifan
Electronegativity is the ability of an atom to attract electrons from other atoms. The factor that affects electronegativity is the pull of the nucleus to the electrons and the radius of the atom.
Elements of a group: the electronegativity is getting smaller and smaller, as the tug-pulling force of the nucleus is weaker. The lower elements in the periodic system tend to release electrons.
Elements such as: electronegativity increasingly greater right. Largest electronegativity at each period is owned by class VII A (halogen elements). The greatest price of electronegativity is found in flour (F) of 4.0, and the smallest price is in franium (Fr) ie 0.7.
Would you please explain the weakness of dalton atomic theory, Rutherford's atomic theory, and the weakness of Bohr's atomic theory?
BalasHapus
BalasHapusIn the above article there is discussed a single substance. What is a single substance, and the difference with mixture.
The material can be classified into a single substance (pure substance) or mixture. A single substance consists of a kind of material, while the mixture consists of two or more types of matter.
HapusRecently there is a mention that there is a little more than the protons, neutrons, and electrons. Have you heard of this and how your response?
BalasHapus