With the help of a simple sketch, explain the shape of the 1s orbital.

The 1s orbital is the simplest of all the orbitals. It is spherical in shape. Here's a step-by-step guide to sketching it:

1. Draw a small circle in the center of your paper. This represents the nucleus of the atom.

2. Draw a larger circle around the first one. This represents the boundary of the 1s orbital. The space between the nucleus and this boundary is where an electron in the 1s orbital could potentially be found.

3. Shade in the area between the nucleus and the boundary of the 1s orbital. This represents the electron cloud, where the electron is most likely to be found.

4. Label the nucleus and the 1s orbital.

Remember, this is a very simplified sketch. In reality, the electron cloud is a three-dimensional space surrounding the nucleus, and the electron could be anywhere within that space.