1 the mass of one mole of electron is ...... mg.
2 copper(I) ions contains .......... electrons in its 3rd orbitals
3 if both K and L shells of an atom are full,what is the total number of electrons contained in them?
4 what is maximum number of electrons which can be accommodated in them?
The mass of 1e x 6.02E23 = ? Then change to mg.
2. Cu = 1s2 2s2 2p6 3s2 3p6 3d10 4s1
So remove the outside electron to make Cu^+ and it's 3d?
3. We have what? 2 electrons in K shell and 8 in the second?
4.Maximum number of electrons in a shell = 2N2
To answer these questions, we need to have some basic understanding of atomic structure and electron configuration. Let's go through each question one by one.
1. The mass of one mole of electrons:
To find the mass of one mole of electrons, we first need to know the molar mass of an electron. The molar mass of an element is determined by summing up the atomic masses of its individual atoms in units of grams per mole. However, electrons are subatomic particles and their mass is extremely small compared to atoms.
The atomic mass unit (amu) is often used to express the mass of subatomic particles. 1 amu is equal to 1/12th the mass of a carbon-12 atom. The electron has a mass of approximately 0.00054858 amu.
To convert this to milligrams:
0.00054858 amu * 1 g / 6.022 x 10^23 amu * 1000 mg / 1 g ≈ 9.108 mg
Therefore, the mass of one mole of electrons is approximately 9.108 milligrams.
2. Copper(I) ions and electrons in its 3rd orbitals:
The electronic configuration of copper (Cu) is [Ar] 3d^10 4s^1. Copper(I) ions have lost one electron, which means they have the configuration [Ar] 3d^10.
In the 3rd orbitals, the d subshell can hold a maximum of 10 electrons. Therefore, copper(I) ions in their 3rd orbitals contain 10 electrons.
3. Total number of electrons when both K and L shells are full:
The K shell represents the 1st energy level, and the L shell represents the 2nd energy level. The maximum number of electrons that can be accommodated in each shell is given by the formula 2n^2, where n is the principal quantum number of the shell.
In the K shell (1st shell), n = 1, so the maximum number of electrons it can hold is 2(1^2) = 2 electrons.
In the L shell (2nd shell), n = 2, so the maximum number of electrons it can hold is 2(2^2) = 8 electrons.
Therefore, if both the K and L shells are full, the total number of electrons would be 2 + 8 = 10 electrons.
4. Maximum number of electrons that can be accommodated:
The maximum number of electrons that can be accommodated in each shell is given by the formula 2n^2, as mentioned earlier. To find the maximum number of electrons that can be accommodated in general, we sum up the maximum number of electrons in each shell up to a given level.
For example, in the first three shells (K, L, M), the maximum number of electrons would be:
2(1^2) + 2(2^2) + 2(3^2) = 2 + 8 + 18 = 28 electrons.
Similarly, for any given number of shells, you would sum up the maximum number of electrons in each shell up to that level to find the maximum number of electrons that can be accommodated.