What atom is indicated by the following electron configuration. 1s^22s^12p^1 ?

To determine the atom indicated by a given electron configuration, we need to look at the number and arrangement of the electrons.

The electron configuration 1s^22s^12p^1 indicates that there are a total of 3 electrons present.

The first digit in each electron subshell (1s^2, 2s^1, 2p^1) represents the principal energy level or shell where the electrons are located.

The second digit indicates the number of electrons present in that subshell.

By referencing the periodic table and its electron configuration, we can identify the atom.

In this case, we start with the first energy level (n=1) and distribute the electrons accordingly:

1s^2 represents the filling of the 1s orbital, which can accommodate a maximum of 2 electrons.

2s^1 represents the filling of the 2s orbital, which can also accommodate a maximum of 2 electrons. However, in this case, only 1 electron is present.

2p^1 represents the filling of the 2p orbital, which can accommodate a maximum of 6 electrons. Again, only 1 electron is present in this case.

Based on this electron configuration, we can identify the atom as hydrogen (H).

Count the electrons and look up the atomic number on the periodic table. But it's an excited atom not in the ground state.