Given the following Unknown atoms with their respective atomic numbers,
X; Atomic number 19,
Y; Atomic number 15,
a. Deduce the identities of the elements X and Y.
b. What are the mass numbers of the two elements X and Y?
c. Calculate the number of Neutrons in the respective elements X and Y
d. Deduce the number of electrons in the respective elements X and Y
e. Give the electronic configurations of the two elements
a. The element with atomic number 19 is potassium (K), and the element with atomic number 15 is phosphorus (P).
b. The mass number of potassium is typically 39, and the mass number of phosphorus is typically 31.
c. To calculate the number of neutrons in an atom, you subtract the atomic number from the mass number. Therefore, the number of neutrons in element X (potassium) is 39 - 19 = 20, and the number of neutrons in element Y (phosphorus) is 31 - 15 = 16.
d. The number of electrons in an atom is equal to the atomic number. Therefore, element X (potassium) has 19 electrons, and element Y (phosphorus) has 15 electrons.
e. The electronic configuration of element X (potassium) is 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹, and the electronic configuration of element Y (phosphorus) is 1s² 2s² 2p⁶ 3s² 3p³.
To answer these questions, we need to have a periodic table of elements as a reference. It is used to find the atomic number and other properties of different elements.
a. To deduce the identities of the elements X and Y, we can match the atomic numbers with the corresponding elements on the periodic table.
- Element X has an atomic number of 19. Referring to the periodic table, we find that the element with atomic number 19 is potassium (K).
- Element Y has an atomic number of 15. Looking at the periodic table, we determine that the element with atomic number 15 is phosphorus (P).
So, the element X is potassium (K) and the element Y is phosphorus (P).
b. The mass number of an element represents the total number of protons and neutrons in its nucleus. However, to determine the mass numbers of elements X and Y, we need additional information, such as the number of protons and neutrons in their respective isotopes.
c. To calculate the number of neutrons in each element, we need to subtract the number of protons (which is equal to the atomic number) from the atomic mass (rounded to the nearest whole number). The atomic mass is usually listed on the periodic table below the element symbol.
d. The number of electrons in an atom is equal to the number of protons, which is represented by the atomic number.
- Element X (potassium) has an atomic number of 19, meaning it has 19 protons and 19 electrons.
- Element Y (phosphorus) has an atomic number of 15, so it has 15 protons and 15 electrons.
e. The electronic configuration of an element shows the arrangement of electrons in its various energy levels or orbitals. To determine the electronic configurations of elements X and Y, we can use the Aufbau principle and the periodic table.
- The electronic configuration of potassium (K) is 1s2 2s2 2p6 3s2 3p6 4s1.
- The electronic configuration of phosphorus (P) is 1s2 2s2 2p6 3s2 3p3.
Please note that the electronic configurations mentioned here represent the ground state (lowest energy state) of the elements.