1.
Elektron beredar mengitari inti atom pada lintasan tertentu bagaikan planet mengitari matahari. Gagasan tersebut merupakan teori atom yang dikemukakan oleh ................
Correct Answer
C. Ernest Rutherford
Explanation
Ernest Rutherford proposed the theory of the atom where electrons orbit around the nucleus in specific paths, similar to planets orbiting the sun. This theory is known as the planetary model of the atom.
2.
MUatan listrik partikel proton, elektron dan neutron berturut-turut adalah .............
Correct Answer
B. +1, -1, 0
Explanation
The electric charge of a proton is +1, the electric charge of an electron is -1, and the electric charge of a neutron is 0.
3.
Perhatikan notasi berikut zXA , A melambangkan ................
Correct Answer
B. Nomor massa
Explanation
The correct answer is "Nomor massa". In the given notation, "z" represents the atomic number, while "A" represents the mass number. The mass number is the total number of protons and neutrons in an atom's nucleus. Therefore, A represents the mass number, not the atomic number, name of the element, protons, or electrons.
4.
Suatu atom dengan notasi 12 X 24 memiliki jumlah proton, elektron dan neutron berturut-turut adalah..............
Correct Answer
A. 12,12,12
Explanation
The atomic number of an atom represents the number of protons in its nucleus. Since the given atom has a notation of 12 X 24, it means that the atomic number is 12, indicating that there are 12 protons in the nucleus. In a neutral atom, the number of electrons is equal to the number of protons. Therefore, there are also 12 electrons in this atom. Neutrons are calculated by subtracting the atomic number from the mass number. In this case, the mass number is 24, so the number of neutrons is 24 - 12 = 12. Therefore, the correct answer is 12,12,12.
5.
Jumlah elektron maksimum dalam setiap kulit harus memenuhi rumus ..............
Correct Answer
A. 2n2
Explanation
The correct answer is 2n2. This is because the formula for the maximum number of electrons in each shell is given by 2n2, where n represents the shell number. This formula is derived from the fact that each shell can hold a maximum of 2n2 electrons, where the first shell (n=1) can hold 2 electrons, the second shell (n=2) can hold 8 electrons, the third shell (n=3) can hold 18 electrons, and so on. Therefore, the formula 2n2 accurately represents the maximum number of electrons in each shell.
6.
Atom 38Sr jika dikonfigurasikan maka pada kulit N akan diisi elektron sebanyak .................
Correct Answer
B. 8
Explanation
When an atom of strontium (Sr) is configured, it will have 38 electrons. The electron configuration of an atom is based on the filling of electron shells or energy levels. The first shell can hold a maximum of 2 electrons, the second shell can hold a maximum of 8 electrons, and the third shell can hold a maximum of 18 electrons. Therefore, when filling the electron shells of strontium, the electrons will first fill the first shell with 2 electrons, and then fill the second shell with 8 electrons. Hence, the correct answer is 8.
7.
Atom yang bermuatan positif disebut ................
Correct Answer
A. Proton
Explanation
Proton adalah partikel subatomik yang memiliki muatan positif. Dalam atom, proton terletak di inti bersama dengan neutron. Elektron, di sisi lain, memiliki muatan negatif dan berputar mengelilingi inti atom. Neutron adalah partikel subatomik yang tidak memiliki muatan, sedangkan anion dan kation adalah ion yang memiliki muatan negatif dan positif secara berturut-turut. Oleh karena itu, jawaban yang tepat untuk pertanyaan ini adalah proton.
8.
Sebuah atom X memiliki nomor atom 20 dan nomor massa 40, apabila atom tersebut dalam keadaan X2+ maka terdapat ........
Correct Answer
C. 20p, 18e, 20n
Explanation
The correct answer is 20p, 18e, 20n. This is because the atomic number of an element represents the number of protons in its nucleus. Since atom X has an atomic number of 20, it means it has 20 protons. The atomic mass of an element represents the total number of protons and neutrons in its nucleus. Since atom X has an atomic mass of 40, it means it has 20 neutrons (40 - 20 = 20). The number of electrons in a neutral atom is equal to the number of protons, so if atom X is in the X2+ state, it means it has lost 2 electrons, resulting in 18 electrons.
9.
Suatu atom mempunyai 3 kulit atom dan 7 elektron valensi. Dalam intinya terdapat 20 neutron. Nomor massa atom itu adalah.....
Correct Answer
E. 37
Explanation
The atomic number of an atom is determined by the number of protons in its nucleus. In this case, the number of valence electrons is given as 7, which indicates that the atom belongs to Group 17 of the periodic table. Group 17 elements have 7 valence electrons, so the atomic number would be 17. The atomic mass is the sum of the protons and neutrons in the nucleus. Given that there are 20 neutrons, the atomic mass would be 37. Therefore, the correct answer is 37.
10.
Suatu unsur memiliki konfigurasi elektron 2, 8, 18, 18, 8, 1 nomor atom unsur tersebut adalah............
Correct Answer
C. 57
Explanation
The given configuration of the electron is 2, 8, 18, 18, 8, 1. This configuration corresponds to the element with atomic number 57, which is Lanthanum (La).
11.
Atom berikut yang memiliki elektron valensi terbesar adalah...............
Correct Answer
D. S nomor atom 18
Explanation
The atom with the highest valence electron is the one with the highest atomic number. In this case, atom S with atomic number 18 has the highest valence electron.
12.
Unsur yang tidak termasuk golongan gas mulia adalah.............
Correct Answer
C. Se
Explanation
The element Se (selenium) does not belong to the noble gas group. Noble gases are a group of elements that are known for their low reactivity and full valence electron shells. They include He (helium), Ne (neon), Kr (krypton), and Rn (radon). Se, on the other hand, belongs to the nonmetal group and has different chemical properties compared to noble gases.
13.
Unsur lantanida dalam SPU bentuk panjang terletak pada ..............
Correct Answer
B. Periode 6 golongan IIIB
Explanation
The correct answer is "periode 6 golongan IIIB." This is because the lanthanide series, which consists of the elements with atomic numbers 57 to 71, is located in the sixth period of the periodic table. Additionally, the IIIB group (or 3B group) is where the lanthanides are placed in the periodic table.
14.
Letak unsur galium ( nomor atom = 31 ) dalam SPU adalah pada.....................
Correct Answer
C. Periode 4, golongan IIIA
Explanation
The correct answer is "Periode 4, golongan IIIA". This is because the question is asking for the location of the element gallium (atomic number = 31) in the periodic table. Gallium is located in period 4, which is the fourth row of the periodic table, and it is in group IIIA, which is the third group from the left.
15.
Diantara unsur-unsur 11Na, 12Mg, 19K, 20Ca, 37Rb yang memiiki energi ionisasi terkecil adalah.................
Correct Answer
E. 37Rb
Explanation
The element with the smallest ionization energy among 11Na, 12Mg, 19K, 20Ca, and 37Rb is 37Rb. Ionization energy refers to the energy required to remove an electron from an atom or ion. As we move down a group in the periodic table, the ionization energy generally decreases due to the increasing atomic size and shielding effect of inner electrons. Rb (Rubidium) is located at the bottom of Group 1 (alkali metals), so it has the largest atomic size and the lowest ionization energy compared to the other elements listed.
16.
Sifat yang mencerminkan mudah tidaknya satu unsur melepas elektron membentuk ion positif adalah...........
Correct Answer
D. Energi ionisasi
Explanation
The correct answer is energi ionisasi. Energi ionisasi refers to the amount of energy required to remove an electron from an atom or ion. The higher the energy ionization, the more difficult it is for an element to lose an electron and form a positive ion. Therefore, the energy ionization reflects the ease or difficulty of an element in releasing electrons to form positive ions.
17.
Diantara unsur berikut : 5P, 15Q, 19R, 31S, 54T yang merupakan unsur satu golongan adalah ..................
Correct Answer
D. P dan S
Explanation
The correct answer is P dan S. Among the given elements, only P and S belong to the same group.
18.
Sifat periodik berikut ini yang tidak benar adalah ...............
Correct Answer
C. Dari kiri ke kanan dlm satu periode kecenderungan melepas elektron bertambah
Explanation
The correct answer states that "Dari kiri ke kanan dlm satu periode kecenderungan melepas elektron bertambah" which translates to "From left to right in a period, the tendency to lose electrons increases." This statement is incorrect because in a period, the tendency to gain electrons increases as we move from left to right across the periodic table.
19.
Diketahui beberapa unsur dg konfigurasi elektron sebagai berikut :
P : 2 8 8 1, Q : 2 8 , R : 2 8 2 S = 2 8 4, T : 2 7
unsur yang memiliki afinitas elektron terbesar adalah ...............
Correct Answer
E. T
Explanation
The element with the electron configuration 2 7 is the element with the largest electron affinity.
20.
Diantara unsur berikut yang memiliki keelektronegatifan terbesar adalah................
Correct Answer
C. Flourin
Explanation
Flourin memiliki keelektronegatifan terbesar di antara unsur-unsur yang tercantum. Keelektronegatifan adalah kemampuan suatu unsur untuk menarik elektron dalam suatu ikatan kimia. Flourin memiliki keelektronegatifan terbesar karena memiliki jumlah proton yang lebih besar dibandingkan unsur-unsur lainnya dalam pilihan tersebut. Hal ini membuatnya memiliki daya tarik yang lebih kuat terhadap elektron dalam ikatan kimia.
21.
Unsur dengan nomor atom 16 akan mencapai kestabilan dengan cara................
Correct Answer
B. Menyerap 2 elektron
Explanation
Unsur dengan nomor atom 16 akan mencapai kestabilan dengan cara menyerap 2 elektron.
22.
Di antara kelompok senyawa berikut yang merupakan senyawa kovalen adalah...............
Correct Answer
B. CO2, CH4 dan HCl
Explanation
The compounds CO2, CH4, and HCl are examples of covalent compounds because they are formed by the sharing of electrons between atoms. In CO2, the carbon atom shares electrons with two oxygen atoms. In CH4, the carbon atom shares electrons with four hydrogen atoms. In HCl, the hydrogen atom shares electrons with the chlorine atom. Covalent compounds typically consist of nonmetals or a combination of nonmetals and metalloids.
23.
Unsur P ( nomor atom 12 ) dan unsur Q ( nomor atom 17 ) dapat membentuk senyawa dengan jenis ikatan dan rumus empiris ........
Correct Answer
B. Ion, PQ2
Explanation
Unsur P (nomor atom 12) dan unsur Q (nomor atom 17) dapat membentuk senyawa dengan jenis ikatan ionik. Dalam senyawa ini, unsur P akan kehilangan 2 elektron dan unsur Q akan menerima 1 elektron. Oleh karena itu, rumus empiris senyawa ini adalah PQ2, menunjukkan bahwa unsur P membentuk 1 ion P2+ dan unsur Q membentuk 2 ion Q-.
24.
Suatu unsur X membentuk berbagai senyawa sbb : Na2X, XCl2, XO2 dan XO3. Dalam SPU unsur X terletak pada golongan.......
Correct Answer
D. VIA
Explanation
The element X forms compounds with the formulas Na2X, XCl2, XO2, and XO3. This indicates that element X belongs to Group VIA.
25.
Diketahui beberapa jenis ion sebagai berikut NH4+, SO42-, Ca2+, PO43- . NO3-, dan Al3+, maka rumus kimia berikut yang tidak benar adalah ...............
Correct Answer
B. (NH4)3NO
Explanation
The given chemical formula (NH4)3NO is incorrect because it violates the rule of charge balance. In this formula, the ammonium ion (NH4+) has a charge of +1, and the nitrate ion (NO3-) has a charge of -1. To achieve charge balance, the formula should have an equal number of positive and negative charges. However, in (NH4)3NO, there are three ammonium ions (+3) and only one nitrate ion (-1), resulting in a net charge of +2. Therefore, the correct formula should have been NH4NO3.