A neutral atom of an element has 2 electrons with n=1, 8 electrons with n=2, and 5 electrons with n=3. Write its electron configuration and find:
A) atomic number B) total number of s electrons
C) total number p electrons
D) total number of protons
E)Paired electrons
F)unpaired electrons
1s2 2s2 2p6 3s2 3p3
Count the electrons; that's the atomic numbr and you didn't need to write the electron configuration to do that. You can count from the problem.
C. Count the p.
D.total protons must = total electrons
E. Can you find them?
The electron configuration is written in the format:
1s² 2s² 2p⁶ 3s² 3p³
Now let's find the information you asked for:
A) Atomic number:
The atomic number is the total number of protons in an atom. Since we know each proton corresponds to one electron, the atomic number would be the sum of the electrons, which is:
2 + 8 + 5 = 15
B) Total number of s electrons:
The s orbitals have a maximum capacity of 2 electrons each.
From the electron configuration, we can see that there are 2 electrons in the 1s orbital, 2 electrons in the 2s orbital, and 2 electrons in the 3s orbital, giving us a total of:
2 + 2 + 2 = 6 s electrons
C) Total number of p electrons:
The p orbitals have a maximum capacity of 6 electrons each.
From the electron configuration, we can see that there are 6 electrons in the 2p orbital and 3 electrons in the 3p orbital, giving us a total of:
6 + 3 = 9 p electrons
D) Total number of protons:
The number of protons is equivalent to the atomic number, so in this case, it is 15.
E) Paired electrons:
Paired electrons are those that are in the same orbital and have opposite spins. Looking at the electron configuration, we can see that the following electrons are paired:
1s², 2s²
F) Unpaired electrons:
Unpaired electrons are those that do not have a partner with opposite spins. From the electron configuration, the unpaired electrons are:
2p³
So the final answers are:
A) Atomic number: 15
B) Total number of s electrons: 6
C) Total number of p electrons: 9
D) Total number of protons: 15
E) Paired electrons: 1s², 2s²
F) Unpaired electrons: 2p³
To write the electron configuration of the neutral atom, we need to place the electrons into their respective shells and subshells according to the rules.
A) Atomic number refers to the number of protons in the nucleus of an atom. Since the atom is neutral, the number of protons is equal to the number of electrons. To find the atomic number, we need to add up the total number of electrons.
Atomic number = 2 + 8 + 5 = 15
B) The total number of s electrons is found by looking at the subshell with the principal quantum number (n) equal to 1. In this case, there are 2 electrons with n=1, which belong to the s subshell.
Total number of s electrons = 2
C) The total number of p electrons is found by looking at the subshell with the principal quantum number (n) equal to 2 and 3. In this case, there are 8 electrons with n=2 and 5 electrons with n=3, which belong to the p subshell.
Total number of p electrons = 8 + 5 = 13
D) The total number of protons is equal to the atomic number, which we found to be 15.
E) Paired electrons are those that occupy the same orbital with opposite spins. To determine the number of paired electrons, we need to examine all the subshells and count the pairs. In this case, we have:
- For the 2s subshell, there are 2 electrons (1 pair).
- For the 2p subshell, there are 6 electrons (3 pairs).
- For the 3p subshell, there are 4 electrons (2 pairs).
Total paired electrons = 1 + 3 + 2 = 6
F) Unpaired electrons are those that occupy an orbital without a partner. To determine the number of unpaired electrons, we subtract the number of paired electrons from the total number of electrons. In this case:
Total number of electrons = 2 + 8 + 5 = 15
Total paired electrons = 6
Unpaired electrons = Total number of electrons - Total paired electrons = 15 - 6 = 9
Therefore, the answers are:
A) Atomic number = 15
B) Total number of s electrons = 2
C) Total number of p electrons = 13
D) Total number of protons = 15
E) Paired electrons = 6
F) Unpaired electrons = 9