Posted inunclassified Chemistry: Structure of Atoms Posted by By Agodirin September 29, 2024No Comments Report a question What's wrong with this question? You cannot submit an empty report. Please add some details. 5 1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950 Created by Agodirin Chemistry: Structure of Atoms Vol 1 1 / 50 1. atm41-Which of the following is not correct about how to write the electronic configuration of an atom A) the shell numbers are written as s, p , d or f B) the number of electrons present is written as superscript after the sub-shell C) the subshells are written before the shell number D) the shell are written as 1,2,3 etc The configuration is written some thing like 1s2-2s2-2p6. the first number is the shell number which is first written as whole number starting from 1 for K, 2 for L , 3 for M etc. then it is followed by the subshell which is s, p,d or f and then the number of electrons in the subshell orbit is written last as superscript. so the 6 in 1p6 is the number of electrons 2 / 50 2. atm2-Which of the following are the components of an atom A) shell and core B) nucleus and shells C) proton and neutron D) nucleus and membrane An atom is composed of a nucleus (containing protons and neutrons) and electron shells (where electrons reside). The other options do not correctly represent the structure of an atom. 3 / 50 3. atm39-if an atom has 12 electrons the last electron will be located in which shell A) first B) third C) fourth D) second The electron configuration for 12 electrons is 1s2, 2s2, 2p6, 3s2, meaning the last electron is in the third shell.( the first shell has 2 electrons, the second shell holds 8 electrons and the remaining 2 go into the third shell 4 / 50 4. atm46-Which of the following has the largest number of electrons in the outermost shell A) 8-oxygen B) 15-phosphorus C) 10-neon D) 19-kalium(potassium) Neon (atomic number 10) has a complete outer shell with 8 valence electrons, which is the maximum for the outermost shell in the second period. Oxygen (8) has 6, phosphorus (15) has 5, and potassium (19) has 1 in its outermost shell. 5 / 50 5. atm48-The number of atoms in one molecule of an element is the A) atomicity B) mole number C) molecular number D) mass number one molecule of Cl is monoatomic, one molecule of oxygen (O2) is diatomic, if the element contains 3 atoms it is triatomic eg , Ozone , O3 if the molecule of the element contains 4 6 / 50 6. atm13-the current standard for estimating the mass of an atom is relative to the mass of A) hydrogen B) nitrogen C) carbon D) oxygen The atomic mass scale is based on the carbon-12 isotope, which is commonly used as the standard reference for atomic masses. However, if you are specifically choosing from the options provided, the most direct answer is "carbon." 7 / 50 7. atm22-An atom as atomic number of 8 and 7 neutrons. What is the number of electrons A) 7 B) 16 C) 15 D) 8 In a neutral atom, the number of electrons equals the number of protons, which is the atomic number. Here, the atomic number is 8, so there are 8 electrons. 8 / 50 8. atm6-Which of the following is not correct. A) The mass on an atom is concentrated in the nucleus B) the mass of electron contributes significantly to mass of the atom C) the mass of proton is similar to mass of neutron D) The mass of the proton contributes significantly to the mass of the atom The mass of an electron is very small compared to that of protons and neutrons, so it does not significantly contribute to the overall mass of the atom. 9 / 50 9. atm30-The regions of the sub-shell of an atom where an electron is likely to be found is the A) home B) orbital C) domain D) spectrum An orbital is a region in an atom where there is a high probability of finding electrons 10 / 50 10. atm27-When the vapor of a naturally occuring element was passed into a mass spectrometer. The spectrometer showed two peaks. Which of the following is correct A) the element has 4 isotopes B) all the atoms of the element are similar C) the element has two isotopes D) the element as three isotopes A mass spectrometer separates particles based on their mass-to-charge ratio. If an element shows two peaks in the mass spectrum, it means that there are two different masses present, which corresponds to the presence of two isotopes of that element. Isotopes are atoms of the same element that have different numbers of neutrons, resulting in different atomic masses 11 / 50 11. atm18-Which of the following is not correct A) The relative atomic mass unit is the average of the atomic masses of its isotopes B) the mass number of an atom is the number of neutrons plus protons in the nucleus C) the relative atomic mass unit can be in fractions D) atomic number can be in fractions Atomic Number: The atomic number of an element is defined as the number of protons in the nucleus of an atom and is always a whole number. It cannot be in fractions. 12 / 50 12. atm25-An element has two isotopes X-23 and X-24 . The isotopes exist in ratio 3:1. what is the relative atomic number of the element A) 23.6 B) 23.3 C) 23.7 D) 23.5 To find the relative atomic mass of the element with isotopes X-23 and X-24 existing in a ratio of 3:1, we can follow these steps:Step-by-Step Calculation: Isotope1 X-23 has a mass1 of 23 and exists in a ratio of 3. And Isotope2 X-24 has a mass2 of 24 and exists in a ratio2 which is 1. Calculate the weighted average:The relative atomic mass AA can be calculated using the formula: A=(mass1×ratio1)+(mass2×ratio2)/(ratio1+ratio2)=(23×3)+(24×1)/3+1=23.25 13 / 50 13. atm12-Which of the following is not correct A) isotopes are atoms of same element with different number of protons B) isotopy contravene's dalton's law of identical atoms in an element C) isotopes have different mass numbers D) Isotopes have different atomic numbers they are atoms of same elements with the same atomic number (Z) but different mass number. This means they have the same number of protons but different number of neutrons in their nucleus 14 / 50 14. atm20-An atom has a mass number of 40 and atomic number of 21. what is the number of electrons A) 19 B) 80 C) 21 D) 40 In a neutral atom, the number of electrons equals the number of protons, which is the atomic number. Here, the atomic number is 21, so there are 21 electrons. 15 / 50 15. atm17-Which of the following is used to measure the atomic mass unit of an atom A) spectrometer B) hydrometer C) thermometer D) electrometer A mass spectrometer is an instrument used to measure the mass-to-charge ratio of ions. It can accurately determine the atomic mass of an atom by analyzing the isotopes present. The other options (electrometer, hydrometer, thermometer) are not used for measuring atomic mass. 16 / 50 16. atm28-Which of the following is not correct A) The electrons in an atom circle continuously around the nucleus B) the I -shell is the innermost shell C) the circular path of the electrons around the nucleus is called the shell D) The K-shell has the lowest energy level In the quantum mechanical model, electrons do not move in fixed circular paths. Instead, they exist in probabilistic orbitals around the nucleus. 17 / 50 17. atm37-The order in which the electrons enter the orbital in the various energy sublevel of an atom is described by A) dalton B) avogadro C) einstein D) aufbau The Aufbau principle states that electrons fill orbitals starting from the lowest energy level to the highest. 18 / 50 18. atm29-Which of the following is not correct A) the electron shells of the atom are labelled KLM etc B) the number of electrons in the L shell is 16 C) each shell may have sub-shells labelled spdf The L shell can hold a maximum of 8 electrons. The total number of electrons in a shell can be calculated using the formula 2n22n2, where nn is the shell number (for L, n=2n=2). 19 / 50 19. atm5-Which of the following are the three subatomic particles of an atom A) proton, neutron and electron B) proton, ion and neutron C) electron, ion and neutron D) electron , ion and protons These are the three fundamental subatomic particles that make up an atom. Protons are positively charged, neutrons are neutral, and electrons are negatively charged. 20 / 50 20. atm33-the d subshell of an atom has how many orbitals A) one B) seven C) five D) three The d-subshell has five orbitals, which can hold a maximum of 10 electrons. 21 / 50 21. atm16-Which of the following relative atomic mas units is not correct A) oxygen is 16 B) carbon is 12 C) hydrogen is 1 D) Nitrogen is 36 The relative atomic mass of nitrogen is approximately 14.01, not 36. The other values are correct: carbon is 12, hydrogen is 1, and oxygen is 16. 22 / 50 22. atm49-Which of the following is not true about the atomic theory ( Dalton’s atomic theory) A) atoms can be created from other atoms B) Atoms of an element are alike C) Matter is made up of small indivisible particles called atoms D) atoms combine in small whole numbers Dalton's atomic theory posits that atoms are indivisible and cannot be created or destroyed in chemical reactions. This statement contradicts that principle, as atoms can only rearrange during reactions but cannot be created from other atoms. 23 / 50 23. atm44-how many electrons can the f subshell hold A) 8 electrons B) 4 electrons C) 10 electrons D) 14 electrons The f subshell has 7 orbitals, and since each orbital can hold 2 electrons, it can hold a total of 7×2=147×2=14 electrons. 24 / 50 24. atm21-An atom as atomic number of 8 and 7 neutrons. What is the mass number A) 8 B) 14 C) 16 D) 15 The mass number can be calculated using the formula: Mass Number=Atomic Number+NeutronsMass Number=Atomic Number+Neutrons For this atom, it would be: 8+7=158+7=15 25 / 50 25. atm14-the current standard for estimating the mass of an atom is relative to the mass of A) Oxygen-17 B) carbon-13 C) carbon-12 D) Oxygen-16 The atomic mass unit (amu) is defined relative to carbon-12, where one amu is one-twelfth of the mass of a carbon-12 atom. This isotope serves as the standard reference point for measuring and comparing the masses of all other atoms. 26 / 50 26. atm15-Which of the following is not correct regarding the process of estimating the mass of an atom A) the mass is estimate relative to Carbon-12 B) there is no unit for mass of an atom C) it is estimated relative to oxygen-16 D) the mass of an atom is presented as a ratio The mass of an atom is actually estimated relative to carbon-12 (¹²C), not oxygen-16 (¹⁶O). The atomic mass unit (amu) is defined based on the mass of carbon-12, where 1 amu is a twelfth of the mass of a carbon-12 atom. 27 / 50 27. atm31-The s-subshell has how many orbitals A) three B) one C) four D) two The s-subshell has one orbital, which can hold a maximum of 2 electrons. 28 / 50 28. atm36-What is the maximum number of electrons that the 4th shell of an atom can hold A) eight B) two C) eighteen D) thirty-two The maximum number of electrons in a shell can be calculated using 2n raised to power 2 or n-squared. For the 4th shell (n=4n=4): 2(4-squared)=2(16)=32 29 / 50 29. atm10-Which of the following is not correct about hydrogen A) it has one electron B) it has one proton C) it has one neutron D) it is a nonmetal Hydrogen typically has one proton and one electron, but it usually has no neutrons in its most abundant isotope (protium). There are isotopes of hydrogen that contain neutrons (like deuterium and tritium), but the most common form of hydrogen (protium) does not have any neutrons. 30 / 50 30. atm8-Which of the following is not correct A) The atomic number(Z) of an element is the number of protons in the nucleus of an atom. B) An atom is electrically neutral C) The charge an atom is the number of protons in the nucleus D) The proton in the nucleus carries the negative charge Protons have a positive charge, while electrons carry a negative charge. This statement is incorrect. 31 / 50 31. atm19-An atom has a mass number of 40 and atomic number of 21. what is the number of neutrons A) 19 B) 21 C) 40 D) 80 The number of neutrons can be calculated using the formula: Neutrons=Mass Number−Atomic NumberNeutrons=Mass Number−Atomic Number For this atom, it would be: 40−21=1940−21=19 32 / 50 32. atm9-The mass number (A) is A) the number of neutrons and electrons in the nucleus B) the number of neutrons and ions in the nucleus C) The number of protons and neutrons in the nucleus D) The number of protons and electrons in the nucleus The mass number is the sum of the number of protons and neutrons in an atom's nucleus. It does not include electrons. 33 / 50 33. atm34-the f subshell of an atom has how many orbitals A) three B) five C) one D) seven The f-subshell has seven orbitals, which can hold a maximum of 14 electrons. 34 / 50 34. atm26-Find the relative atomic mass of the element with isotopes X-10, and X-11, with relative abundance of 70% and 30% respectively. A) 10.1 B) 10.5 C) 10.3 D) 10.8 Isotope A: Has a mass of 10 and a relative abundance of 70% (0.70). Isotope B: Has a mass of 11 and a relative abundance of 30% (0.30). Contribution of A=Mass of A×Relative abundance of A=10×0.70=7.0. Contribution of B=Mass of B×Relative abundance of B=11×0.30=3.3. adding the two gives 10.3 35 / 50 35. atm38-If an atom has 3 electrons the first electron will be located in which shell A) third B) second C) fourth D) first The first electron fills the 1s orbital in the first shell. 36 / 50 36. atm7-Which of the following is not correct A) the proton is neutral B) the electron is negatively charged C) the contribution of electron to mass of the atom is insignificant D) the mass of the atom is concentrated in the nucleus Protons carry a positive charge. The statement about protons being neutral is incorrect. 37 / 50 37. atm32-The p subshell of an atom has how many orbitals A) three B) seven C) five D) one The p-subshell has three orbitals (px, py, pz), which can collectively hold a maximum of 6 electrons. 38 / 50 38. atm1-Which of the following is not correct about dalton's atomic theory A) Compounds are formed by combining atoms B) atoms of an element are identical C) Elements are made of atoms D) When atoms combine they do so in small fractions Dalton's atomic theory states that atoms combine in whole-number ratios to form compounds. The statement about combining in "small fractions" contradicts this principle. 39 / 50 39. atm47-A atom in which the valence shell is completely filled with electron is called A) periodic configuration B) domain atom C) super shell configuration D) noble gas configuration Atoms with a fully filled valence shell typically resemble noble gases and are chemically inert (non-reactive). This configuration is stable and is often referred to as the noble gas configuration. 40 / 50 40. atm45-how many electrons can the d subshell hold A) 10 electrons B) 18 electrons C) 14 electrons D) 8 electrons The d subshell has 5 orbitals, and since each orbital can hold 2 electrons, it can hold a total of 5×2=105×2=10 electrons. 41 / 50 41. atm4-Which of the following form the nucleus of an atom A) proton and ion B) proton and neutron C) neutron and electron D) proton and electron The nucleus of an atom is made up of protons and neutrons. Electrons are not part of the nucleus; they orbit around it. 42 / 50 42. atm23-An element has two isotopes X-20 and X-22 . The isotopes exist in ratio 3:1. what is the relative atomic number of the element A) 22.5 B) 20 C) 20.5 D) 22 To find the relative atomic mass of the element with isotopes X-20 and X-22 existing in a ratio of 3:1, we can use the following calculation:Step-by-Step Calculation:Identify the isotopes and their ratios: Isotope1 X-20 has a mass1 of 20 and exists in a ratio1= 3. Isotope2 X-22 has a mass2 of 22 and exists in a ratio2 of 1. Calculate the weighted average:The relative atomic mass formula: =(mass1×ratio1)+(mass2×ratio2)/(ratio1+ratio2). So if we plug the values into the formula: A=(20×3)+(22×1)/(3+1)= 22.5 43 / 50 43. atm42-when filling the electronic configuration of an atom according to energy level, which of the following is not correct A) the 1s comes before the 2p B) 4f comes before the 5d C) 4s comes before the 3p D) 5s comes before the 4d filling the orbitals according to the energy level. Follow the order: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p 44 / 50 44. atm24-Find the relative atomic mass of the element with isotopes X-16, X-17, and X-18 existing in a ratio of 3:1:1 A) 17.4 B) 17.6 C) 18.6 D) 16.6 To find the relative atomic mass of the element with isotopes X-16, X-17, and X-18 existing in a ratio of 3:1:1, we can use the following calculation: Step-by-Step Calculation:Identify the isotopes and their ratios:Isotope1 X-16 has a mass1 of 16 and exists in a ratio1 which is3. Then Isotope2 X-17 has a mass2 of 17 and exists in a ratio2 which is 1. Finally Isotope3 X-18 has a mass3 of 18 and exists in a ratio3 with is 1. Calculate the weighted average:The relative atomic mass =(mass1×ratio1)+(mass2×ratio2)+(mass3×ratio3)/(ratio1+ratio2+ratio3). Plugging the values into the forula: =(16×3)+(17×1)+(18×1)/(3+1+1)=16.6 45 / 50 45. atm50-An atom is electrically neutral because A) it has equal number of protons and electrons B) it has equal number of neutrons and electrons C) it has neutrons in its nucleus D) it has protons in its nucleus An atom is electrically neutral when it has the same number of positively charged protons in the nucleus as negatively charged electrons surrounding the nucleus. This balance results in no overall charge. 46 / 50 46. atm43-The valence electron of an atom are the electrons in A) the innermost shell B) the middle shell C) the outermost shell D) the first shell Valence electrons are the electrons in the highest energy level (outermost shell) of an atom and are involved in chemical bonding. 47 / 50 47. atm35-What is the maximum number of electrons each orbital of an atom can hold A) five B) four C) three D) two Each orbital can hold a maximum of 2 electrons due to the Pauli exclusion principle. 48 / 50 48. atm40-If an atom has 16 protons, the last electron will be located in which shell A) first B) fourth C) third D) second The correct notation places the shell number before the subshell letter (e.g., 2s2s, 3p3p). The other statements are accurate in their descriptions. 49 / 50 49. atm3-Which of the following form the shell of atoms A) neutron B) ion C) electron D) proton Electrons occupy the shells (energy levels) around the nucleus of an atom. Protons and neutrons are found in the nucleus. 50 / 50 50. atm11-An atom has a mass number of 27 and and atomic number of 17. which of the following is not correct A) the number of electrons is 17 B) the number of protons is 17 C) the atom has a neutral charge D) the number of neutrons is 9 Key Definitions:Atomic Number (Z): The number of protons in an atom, which also determines the element's identity. Mass Number (A): The total number of protons and neutrons in the nucleus of an atom. Neutrons: Calculated as the mass number minus the atomic number (A - Z). Electrons: In a neutral atom, the number of electrons equals the number of protons. Given: Mass Number (A) = 27 and Atomic Number (Z) = 17. Calculations: Number of Protons: This is equal to the atomic number..Protons = 17. Number of Neutrons: This is calculated as follows: Neutrons = Mass Number - Atomic Number = 27 - 17 = 10 Number of Electrons: In a neutral atom, the number of electrons equals the number of protons. Electrons = 17 Your score is LinkedIn Facebook Twitter VKontakte Restart quiz Thank you Send feedback Share via: Facebook X (Twitter) LinkedIn More Agodirin View All Posts Post navigation Previous Post Chemistry: Matter and Separation Techniques MCQ paper 2Next PostChemistry: Periodic Table Volume 1
