1.
Elektron dapat berpindah dari suatu lintasan ke lintasan yang lain sambil menyerap atau memancarkan energi. Teori ini merupakan penyempurnaan teori atom Rutherford yang dikemukakan oleh . . . .
Correct Answer
B. Bohr
Explanation
The correct answer is Bohr because his theory of the atom improved upon Rutherford's model by introducing the concept of electron energy levels or shells. According to Bohr's theory, electrons can move from one orbit to another by absorbing or emitting energy. This theory successfully explained the stability of atoms and the spectral lines observed in the emission and absorption of light.
2.
Model atom Dalton digambarkan sebagai bola yang berbentuk bulat masif. Kelemahan model atom ini adalah . . . .
Correct Answer
A. Belum mengemukakan adanya partikel penyusun atom
Explanation
The correct answer is "Belum mengemukakan adanya partikel penyusun atom". This is because the Dalton model of the atom depicted it as a solid, spherical ball, but it did not propose the existence of subatomic particles that make up the atom. It did not account for the presence of protons, neutrons, and electrons within the atom.
3.
Pernyataan yang tepat mengenai atom dan partikel penyusun atom adalah . . . .
Correct Answer
E. Elektron bermuatan negatif dan bergerak mengelilingi proton
Explanation
The correct answer states that electrons are negatively charged particles that move around the nucleus of an atom, which is made up of protons. This is a basic understanding of atomic structure, where electrons orbit the nucleus in specific energy levels. Protons, on the other hand, are positively charged particles located in the nucleus of an atom. This explanation accurately describes the arrangement of particles in an atom.
4.
Tentukan jumlah proton, elektron dan neutron dari unsur N yang mempunyai nomor masa 15 dan nomor atom 7....
Correct Answer
E. P = 7, n = 8 dan e =7
Explanation
The correct answer is p = 7, n = 8, and e = 7. The atomic number (number of protons) of an element determines its identity, so since the element is N (nitrogen) with an atomic number of 7, there are 7 protons. The mass number (number of protons + neutrons) is 15, so the number of neutrons is 15 - 7 = 8. Since the element is neutral, the number of electrons is equal to the number of protons, so there are 7 electrons.
5.
Jika nomor massa unsur A adalah 30 dan A mempunyai elektron sebanyak 12 maka jumlah neutron unsur A adalah . . .
Correct Answer
E. 18
Explanation
The number of neutrons in an atom is determined by subtracting the atomic number (which is equal to the number of protons) from the atomic mass (which is equal to the sum of protons and neutrons). In this case, the atomic mass of element A is given as 30 and the number of electrons is given as 12. Since the atomic mass includes both protons and neutrons, we can subtract the atomic number (which is equal to the number of protons) from the atomic mass to find the number of neutrons. Therefore, the number of neutrons in element A is 30 - 12 = 18.
6.
Perhatikan notasi suatu unsur X dibawah ini, dalam atom x tersebut terdapat...
Correct Answer
D. 16 proton, 16 elektron dan 14 neutron
Explanation
The given answer is correct because the atomic number of an element is determined by the number of protons in its nucleus. Since the element X has 16 protons, it must have an atomic number of 16. The number of electrons in a neutral atom is equal to the number of protons, so X must also have 16 electrons. The mass number of an element is determined by the sum of its protons and neutrons. Since X has 14 neutrons, the total number of particles in its nucleus is 14+16=30.
7.
Diantara atom berikut, yang mempunyai pasangan isotop adalah...
Correct Answer
E. Atom
8.
Perhatikan atom-atom berikut: 8A15; 7B15; 5C14; 7D14. Atom yang merupakan isoton adalah…
Correct Answer
A. A dan D
Explanation
Isotones are atoms that have the same number of neutrons but different number of protons. In this case, atom A has 8 protons and atom D has 7 protons, but both have 15 neutrons. Therefore, atom A and D are isoton.
9.
Atom 2411Na berisobar dengan atom….
Correct Answer
A. Option
10.
Konfigurasi elektron unsur X dengann nomor atom 53 adalah...
Correct Answer
C. 2 8 18 18 7
Explanation
The electron configuration of an element is a representation of how the electrons are distributed among the energy levels and orbitals in an atom. In this case, the element with an atomic number of 53 is iodine (I). The electron configuration of iodine is 2 8 18 18 7, which means that there are 2 electrons in the first energy level, 8 electrons in the second energy level, 18 electrons in the third energy level, 18 electrons in the fourth energy level, and finally 7 electrons in the fifth and outermost energy level.
11.
Ion X2+ mempunyai konfigurasi elektron 2-8-8. Nomer atom X adalah…
Correct Answer
D. 20
Explanation
The configuration of Ion X2+ is given as 2-8-8, which means it has 2 electrons in the first energy level, 8 electrons in the second energy level, and 8 electrons in the third energy level. To determine the atomic number of X, we need to add up the total number of electrons in all the energy levels. Adding up the electrons in each level, we get 2 + 8 + 8 = 18. However, since the ion has a positive charge of 2+, it means it has lost 2 electrons. Therefore, the atomic number of X would be 18 + 2 = 20.
12.
Suatu atom A dengan konfigurasi elektron 2-8-8-2, maka ….
Correct Answer
E. Nomer atom A = 20
Explanation
The correct answer is "nomer atom A = 20". This is because the question states that the atom A has an electron configuration of 2-8-8-2, which corresponds to the element calcium (atomic number 20). The atomic number represents the number of protons in an atom, which determines its identity. Therefore, the correct answer is that the atomic number of atom A is 20.
13.
Diantara unsur di bawah ini yang mempunyai elektron valensi paling sedikit yaitu unsur dengan lambang...
Correct Answer
D. Option
Explanation
The answer option has the least number of valence electrons among the given elements.
14.
Konfigurasi electron 15P yang paling tepat adalah….
Correct Answer
B. 1s2 2s2 2p6 3s2 3p3
Explanation
The electron configuration of an element represents the arrangement of electrons in its atomic orbitals. The correct answer, "1s2 2s2 2p6 3s2 3p3," indicates that the element has a total of 15 electrons. The numbers and letters represent the different energy levels (1, 2, 3) and sublevels (s, p) that the electrons occupy. The superscript numbers represent the number of electrons in each sublevel. Therefore, this electron configuration shows that there are 2 electrons in the 1s sublevel, 2 electrons in the 2s sublevel, 6 electrons in the 2p sublevel, 2 electrons in the 3s sublevel, and 3 electrons in the 3p sublevel.
15.
Suatu atom tereksitasi mempunyai konfigurasi elektron : 1s2 2s2 2p6 3s2 3p6 4s2 3d5. Di dalam tabel sistem periodik, unsur dari atom tersebut terdapat pada …
Correct Answer
B. Golongan VIIB periode 4
Explanation
The electron configuration of the excited atom indicates that it has 5 electrons in the 3d sublevel, which corresponds to the 5th period of the periodic table. The 4s sublevel is filled with 2 electrons, indicating that it is in the 4th period. Additionally, the 3s and 3p sublevels are filled with 2 and 6 electrons respectively, indicating that it is in the 3rd period. Therefore, the atom belongs to Group VIIB and Period 4 of the periodic table.
16.
Konfigurasi electron ion X2- memiliki kofigurasi elektron 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 . maka X memiiki nomor atom…
Correct Answer
B. 34
Explanation
The electron configuration given for the X2- ion is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6. This configuration indicates that the ion has gained two extra electrons compared to the neutral atom. By counting the number of electrons in the configuration, we can determine the atomic number of the neutral atom. In this case, there are a total of 34 electrons, so the neutral atom of X must have an atomic number of 34. Therefore, the correct answer is 34.
17.
Ion berikut yang mempunyai konfigurasi electron 1s2 2s2 2p6 3s2 3p6 3d5 ….
Correct Answer
C. 25Mn2+
Explanation
The electron configuration 1s2 2s2 2p6 3s2 3p6 3d5 belongs to the element manganese (Mn). The number 25 in the answer choice 25Mn2+ represents the atomic number of manganese, which indicates that it has 25 electrons. The "+2" in Mn2+ indicates that manganese has lost two electrons, resulting in a positive charge of +2. Therefore, the correct answer is 25Mn2+.
18.
Berikut ini adalah bilangan kuantum yang benar dari electron valensi 20X adalah…
Correct Answer
D. N=4; l=0; m=0; s= -1/2
Explanation
The given answer n=4; l=0; m=0; s= -1/2 represents the correct set of quantum numbers for the valence electron of the element 20X. The principal quantum number (n) indicates the energy level of the electron, and in this case, it is 4. The angular momentum quantum number (l) represents the shape of the electron's orbital, and it is 0 for an s orbital. The magnetic quantum number (m) determines the orientation of the orbital, and it is 0 for an s orbital. The spin quantum number (s) determines the spin direction of the electron, and it is -1/2 in this case.
19.
Suatu atom mempunyai konfigurasi elektron : 1s2 2s2 2p6 3s2 3p6 4s2 3d1. Di dalam tabel sistem periodik, unsur dari atom tersebut terdapat pada …
Correct Answer
A. N=3; l=2; m=-2; s= +1/2
Explanation
The given configuration of the electron indicates that the atom belongs to the 3rd energy level (n=3) and the 2nd sublevel (l=2). The value of m represents the magnetic quantum number, which determines the orientation of the orbital within the sublevel. In this case, m=-2 indicates that the orbital is oriented in the -2 direction. The value of s represents the spin quantum number, which describes the spin of the electron. A value of +1/2 indicates that the electron is spinning in the clockwise direction. Therefore, the atom is located in the energy level 3, sublevel 2, with an orbital orientation of -2 and a clockwise spin.
20.
Apabila unsur- unsur disusun menurut kenaikan massa atom relatifnya, ternyata unsur- unsur yang berselisih satu oktaf menunjukkan persamaan sifat. Kenyataan ini dinyatakan oleh…
Correct Answer
B. A.R. Newlands
Explanation
A.R. Newlands is the correct answer because he proposed the Law of Octaves, which states that when elements are arranged in order of increasing atomic mass, every eighth element displays similar properties. This observation was an early attempt to classify and organize the elements, and it laid the foundation for the development of the periodic table.
21.
Unsur yang terletak satu periode dalam sistem periodik mempunyai…
Correct Answer
D. Jumlah kulit elektron sama
Explanation
The correct answer is "jumlah kulit elektron sama" which translates to "the same number of electron shells". This means that the elements in the same period of the periodic table have the same number of electron shells or energy levels. The period number indicates the number of occupied electron shells in an atom of an element.
22.
Kelompok unsur yang membentuk triade yaitu . . . .(massa atom Li=7; Na=23; K=39; Ca=40; S=32; Cl=35,5 ; Mn=55 ; Sr=88,5 ; Se=79 ; Br=80 ; Ba=137 ; Te=128)
Correct Answer
D. Ca, Sr, dan Ba
Explanation
The correct answer is Ca, Sr, and Ba. The question is asking for the group of elements that form a triad. A triad is a group of three elements that have similar chemical properties and are arranged in order of increasing atomic mass. In this case, Ca (atomic mass 40), Sr (atomic mass 88.5), and Ba (atomic mass 137) form a triad because they have similar chemical properties and their atomic masses increase in order.
23.
Konfigurasi elektron unsur X adalah : 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p4Dalam sistem periodik unsur, X terletak pada ...
Correct Answer
B. Golongan VIA periode 4
Explanation
The electron configuration given for element X indicates that it has 4 valence electrons in its outermost energy level. This corresponds to group VIA in the periodic table, which includes elements like oxygen and sulfur. Additionally, the given electron configuration also indicates that element X is in the 4th period. Therefore, the correct answer is "golongan VIA periode 4."
24.
Nomor atom unsur K = 19. Konfigurasi elektron ion K+ adalah … .
Correct Answer
A. 1s2 2s2 2p6 3s2 3p6
Explanation
The configuration of the K+ ion is 1s2 2s2 2p6 3s2 3p6. This is because the K atom has 19 electrons, and when it loses one electron to become a K+ ion, it loses the electron in the 4s orbital. The remaining electrons fill up the 1s, 2s, 2p, 3s, and 3p orbitals following the Aufbau principle and the Pauli exclusion principle. Therefore, the correct configuration for the K+ ion is 1s2 2s2 2p6 3s2 3p6.
25.
Nomor atom Al = 13, maka kulit valensi dari atom unsur Al adalah … .
Correct Answer
B. 3s dan 3p
Explanation
The valence shell of an atom refers to the outermost shell that contains electrons. In the case of aluminum (Al) with an atomic number of 13, the electron configuration is 1s2 2s2 2p6 3s2 3p1. The valence shell consists of the 3s and 3p orbitals, which contain a total of 3 electrons. Therefore, the correct answer is 3s dan 3p.
26.
Konfigurasi elektron yang benar untuk unsur X dengan nomor atom 33 adalah …
Correct Answer
E. 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p3
Explanation
The correct answer is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p3. This is the correct electron configuration for the element with atomic number 33. The electron configuration represents the arrangement of electrons in the atom's energy levels and orbitals. In this case, the electron configuration shows that there are 2 electrons in the 1s orbital, 2 electrons in the 2s orbital, 6 electrons in the 2p orbital, 2 electrons in the 3s orbital, 6 electrons in the 3p orbital, 10 electrons in the 3d orbital, 2 electrons in the 4s orbital, and 3 electrons in the 4p orbital. This configuration corresponds to the element with atomic number 33, which is arsenic (As).
27.
Pernyataan yang benar untuk unsur-unsur dalam satu golongan adalah...
Correct Answer
D. Memiliki electron valensi yang sama
Explanation
The correct answer is "Memiliki electron valensi yang sama" because elements in the same group on the periodic table have the same number of valence electrons. Valence electrons are the electrons in the outermost energy level of an atom and they determine the chemical properties of an element. Therefore, elements in the same group have similar chemical properties due to their same number of valence electrons.
28.
Pasangan unsur-unsur di bawah ini yang memiliki elektron valensi sama adalah …
Correct Answer
E. 12 Mg dan 20 Ca
Explanation
The pair of elements that have the same valence electrons is 12 Mg and 20 Ca. Both magnesium (Mg) and calcium (Ca) belong to Group 2 of the periodic table, which means they have 2 valence electrons.
29.
Unsur 14X mempunyai sifat yang sangat mirip dengan unsur bernomor ...
Correct Answer
A. 32
Explanation
Unsur 14X memiliki sifat yang sangat mirip dengan unsur bernomor 32.
30.
Sifat yang mencerminkan mudah tidaknya suatu unsure melepas electron adalah...
Correct Answer
C. Energy ionisasi
Explanation
Energy ionisasi adalah sifat yang mencerminkan seberapa mudah suatu unsur melepaskan elektron. Semakin tinggi energi ionisasi suatu unsur, semakin sulit bagi unsur tersebut untuk melepaskan elektron. Jadi, energi ionisasi adalah faktor yang menentukan seberapa mudah atau sulit suatu unsur melepaskan elektron.
31.
Dalam urutan unsure 8O, 9F, dan 10Ne, jari-jari atom akan semakin…
Correct Answer
B. Berkurang
Explanation
Dalam urutan unsure 8O, 9F, dan 10Ne, jari-jari atom akan berkurang. Hal ini disebabkan oleh penambahan proton dan neutron dalam inti atom yang menyebabkan peningkatan tarikan elektron terhadap inti atom. Seiring dengan penambahan proton dan neutron, jumlah elektron di sekitar inti atom juga bertambah. Karena tarikan elektron terhadap inti atom semakin kuat, jari-jari atom akan semakin berkurang.
32.
Diantara pernyataan berikut yang bukan merupakan sifat periodic unsure adalah…
Correct Answer
E. Dari atas ke bawah dalam satu golongan energy ionisasi semakin besar
Explanation
The correct answer is "Dari atas ke bawah dalam satu golongan energy ionisasi semakin besar" which means "From top to bottom within a group, ionization energy increases." This statement is incorrect because ionization energy generally decreases from top to bottom within a group. Ionization energy is the energy required to remove an electron from an atom, and as you move down a group, the outermost electrons are further away from the nucleus and are therefore less strongly attracted to it. This makes it easier to remove an electron and results in lower ionization energy.
33.
Diantara unsure-unsur di bawah ini, yang memiliki keelktronegatifan paling besar adalah…
Correct Answer
C. F dengan nomor atom 9
Explanation
Electronegativity is the ability of an atom to attract electrons towards itself in a chemical bond. It increases as you move across a period from left to right in the periodic table. Since fluorine (F) is the element with the lowest atomic number among the given options, it is located on the far left of the periodic table. This means that it has the highest electronegativity compared to the other elements. Therefore, F with atomic number 9 has the highest electronegativity among the given elements.
34.
Unsur berikut yang terletak pada periode ketiga adalah…
Correct Answer
D. Al dengan nomor atom 13
Explanation
Aluminium (Al) is the element with atomic number 13, which means it has 13 protons in its nucleus. The periodic table is organized in such a way that elements with similar properties are grouped together in the same period. The third period of the periodic table consists of elements with atomic numbers 11 to 18, so Al (with atomic number 13) falls within this range and is located in the third period.
35.
Unsur yang mempunyai afinitas elektron terbesar adalah . . . .
Correct Answer
B. 17Cl
Explanation
Chlorine (Cl) has the highest electron affinity among the given elements. Electron affinity refers to the amount of energy released or absorbed when an atom gains an electron. Chlorine has a high electron affinity because it has a strong attraction for an additional electron to complete its outer electron shell. This is due to its high effective nuclear charge and the relatively small size of its atomic radius. Therefore, chlorine has the highest electron affinity compared to silicon (Si), calcium (Ca), gallium (Ga), and selenium (Se).