The electron dot (Lewis dot) symbol for an O atom has __ 8 dots because its atomic number is 8 2 dots because it is in row 2 16 dots because its atomic mass is 16 6 dots because it is in group 16

## Step 1<br />The electron dot (Lewis dot) symbol for an atom represents the valence electrons, which are the electrons in the outermost shell of an atom. These electrons are involved in forming bonds with other atoms.<br /><br />## Step 2<br />The atomic number of oxygen is 8, which means it has 8 protons in its nucleus. However, the number of electrons in a neutral atom is equal to the number of protons. Therefore, oxygen has 8 electrons.<br /><br />## Step 3<br />The electron configuration of oxygen is \(1s^2 2s^2 2p^4\). This means that oxygen has 2 electrons in the first shell (1s), 2 electrons in the second shell's s orbital (2s), and 4 electrons in the second shell's p orbital (2p).<br /><br />## Step 4<br />The electrons in the outermost shell of an atom are the valence electrons. For oxygen, the outermost shell is the second shell, which contains 2 electrons in the 2s orbital and 4 electrons in the 2p orbital, making a total of 6 valence electrons.<br /><br />## Step 5<br />Therefore, the electron dot symbol for oxygen has 6 dots, representing its 6 valence electrons. This is not determined by its atomic number, atomic mass, or its position in the periodic table (row or group), but by its electron configuration.