The atomic number of lithium is 3. How many neutrons does an atom of lithium have if it is represented by the symbol shown below?
7Li
A. 2 neutrons
B. 13 neutrons
C. 4 neutrons
D. 7 neutrons
The atomic number of fluorine is 9. How many electrons does an ion of fluorine have if it is represented by the symbol shown below?
19F1-
A. 8 electrons
B. 9 electrons
C. 10 electrons
D. 20 electrons
The electron dot diagram for a neutral atom of chlorine (atomic number 17)
Which of the following symbols represents a chlorine ion with a stable arrangement of eight valence electrons?
electron dot diagram of chlorine
A. 35Cl1-
B. 35Cl2-
C. 35Cl1+
D. 35Cl
An ion of iron has an 26 protons, 30 neutrons, and 23 electrons. What are its atomic number, atomic mass, and net charge?
A. atomic number = 26, atomic mass = 56, net charge = 3+
B. atomic number = 26, atomic mass = 56, net charge = 3-
C. atomic number = 30, atomic mass = 56, net charge = 3+
D. atomic number = 56, atomic mass = 26, net charge = 3-
A lithium atom contains 3 protons, 4 neutrons and 3 electrons. What would be formed if one proton is added to this atom?
A. a lithium ion
B. a different isotope of lithium
C. a beryllium ion
D. a neutral atom of beryllium
Answers
Answer:atomic number=26,atomic mass=56,net charge 3-
Explanation:
Answer: The correct answers are
1-(C)4 neutrons
2-(C)10 electrons
3- (A)35Cl⁻¹
4-(B) atomic number = 26, atomic mass = 56, net charge = 3-
5- (C) a beryllium ion.
Explaination:
1) The atomic number of lithium is 3, which means that an atom of lithium has 3 protons in its nucleus. The mass number of an isotope is the sum of the number of protons and neutrons in its nucleus. In the case of 7Li, the mass number is 7, which means that there are 7 - 3 = 4 neutrons.
2) The atomic number of fluorine is 9, which means that a neutral fluorine atom has 9 electrons. An ion of fluorine is formed when it gains or loses electrons. In this case, the ion is represented by 19F⁻¹, which means that it has a charge of -1. To have a charge of -1, it must have lost 1 electron compared to a neutral fluorine atom. Hence, an ion of fluorine represented by 19F⁻¹ has 9 + 1 = 10 electrons.
3) Chlorine has an electron configuration of [Ne] 3s² 3p⁵, with 7 valence electrons. To achieve a stable arrangement of eight valence electrons, chlorine must gain one electron to form an anion (negatively charged ion) with the electron configuration [Ne] 3s² 3p⁶. Hence, a chlorine ion with a stable arrangement of eight valence electrons is represented by the symbol 35Cl⁻¹
4) The atomic number of an element is the number of protons in its nucleus, which determines its identity. In this case, the ion has 26 protons, so its atomic number is 26.
The atomic mass of an element is the sum of the number of protons and neutrons in its nucleus. In this case, the ion has 30 neutrons, so its atomic mass is 26 (protons) + 30 (neutrons) = 56.
The net charge of an ion is calculated by subtracting the number of electrons from the number of protons. In this case, the ion has 23 electrons, so its net charge is 26 (protons) - 23 (electrons) = 3-.
5) A lithium atom contains 3 protons, 4 neutrons, and 3 electrons. If one proton is added to this atom, the number of protons increases to 4, so with 4 protons, this atom is no longer lithium, but instead becomes beryllium. The addition of one proton creates a beryllium ion with a charge of +1, since it now has 4 protons and only 3 electrons.
To learn more about Neutrons, refer these links.
https://brainly.in/question/374445
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