Write the condensed electron configurations for the following atoms and indicate how many unpaired electrons each has. for Ca and Y
for Ca i got [Ar] 4s2 but it got cuonted wrong
I suspect it was counted wrong because you didn't say how many unpaired electrons. There are zero in Ca.
To find the condensed electron configuration for calcium (Ca), we can start by writing the electron configuration for argon (Ar), which is the preceding noble gas.
The electron configuration for argon is: 1s2 2s2 2p6 3s2 3p6.
After argon, calcium has an atomic number of 20. This means that calcium has 20 electrons. We can now continue by filling up the remaining electrons in calcium's electron configuration.
Calcium's electron configuration is: [Ar] 4s2.
Now, let's determine the number of unpaired electrons in calcium. Since calcium's electron configuration in the ground state ends in 4s2, there are two electrons in the 4s sublevel. However, these two electrons have opposite spins, meaning they are paired. Therefore, calcium has zero unpaired electrons.
For yttrium (Y), we can follow a similar approach.
The electron configuration for yttrium starts with the preceding noble gas, krypton (Kr), which has the configuration: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6.
Yttrium has an atomic number of 39, meaning it has 39 electrons. We continue by filling up the remaining electrons in yttrium's electron configuration.
Yttrium's electron configuration is: [Kr] 5s2 4d1.
To find the number of unpaired electrons in yttrium, we look at the last sublevel that has electrons, which is the 4d sublevel with one electron. Since this electron is unpaired, yttrium has one unpaired electron.