Knowee
Questions
Features
Study Tools

The last entering electron in an element has quantum number n = 3, l = 2, m = + 2 and s = + 1 /2.The atomic number of the element will be(a) 13 (b) 21 (c) 29 (d) 39

Question

The last entering electron in an element has quantum number n = 3, l = 2, m = + 2 and s = + 1 /2.The atomic number of the element will be(a) 13 (b) 21 (c) 29 (d) 39

🧐 Not the exact question you are looking for?Go ask a question

Solution

To determine the atomic number of the element, we need to understand the meaning of the given quantum numbers.

The quantum number n represents the principal energy level or shell of the electron. In this case, n = 3, indicating that the electron is in the third energy level.

The quantum number l represents the azimuthal or orbital angular momentum quantum number. It determines the shape of the orbital. Here, l = 2, which corresponds to the d orbital.

The quantum number m represents the magnetic quantum number. It specifies the orientation of the orbital in space. The value m = +2 indicates that the electron is in the d orbital with an orientation of +2.

The quantum number s represents the spin quantum number. It describes the spin of the electron. The value s = +1/2 indicates that the electron has a spin of +1/2.

Now, we can determine the atomic number of the element. The atomic number is equal to the number of protons in the nucleus of an atom. In a neutral atom, the number of electrons is also equal to the atomic number.

Since the electron in question is the last entering electron, it will occupy the highest energy level available. In this case, it is the third energy level (n = 3).

The maximum number of electrons that can be accommodated in the third energy level is given by the formula 2n^2. For n = 3, the maximum number of electrons is 2(3)^2 = 18.

To determine the atomic number, we need to find the position of the electron in the electron configuration. The electron configuration for the given quantum numbers is 3d^2.

The atomic number is equal to the number of electrons, so the atomic number of the element will be the number of electrons in the 3d orbital, which is 2.

Therefore, the correct answer is (a) 13, as it is the only option that corresponds to an atomic number of 13.

This problem has been solved

Similar Questions

The four quantum numbers of distiguished electron of an atom are as followUsing the above information answer the following questions.i) How many electrons present in outer most orbit?ii) Write the electron configuration of this element?iii) What is the atomic number of this element?iv) What is the shape of the last electron orbital?

An element(M) has atomic weight 39. It electronic configuration is 1s22s22p63s23p64s1. The true statement for that element is It is an electronegative element It is a transition element It is isotonic with 18Ar36 It belongs to 4th period

An atom of an element A has three electrons in its outermost orbit and that of B has six electrons in its outermost orbit. The formula of the compound between these two will be :

What is the Principle Quantum number? If electrons configuration of an element is  1s22s22p63s2

An element 'X' have 3 electrons in its outer most third orbit.What will be its Atomic number and Number of proton in it.Write its Electronic configuration?

1/3

Upgrade your grade with Knowee

Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.