Where does the dot go on the H ? On the side or above? I do know that there is only one because of where it is located on the periodic table.
Also with Ca^2+
wouldn't the charge cancel? so what would you write?
H has one electron in the first orbital ring. Unlike the elements further down than H and He, those two elements can only fit 2 electrons in that first shell.
So an H atom would have one dot anywhere in the shell. When H forms a Covalent bond there are two dots in that shell, one of those belonging to the other element. Then that shell is full and the compound is happy.
Ca+2 is missing two electrons in its outer shell The neutral Ca atom has 20 electrons
2 fill the first shell
8 more in the second so 10 so far
8 more in the third so 18 so far
That puts 2 in the outer shell which is happier with 0 or 8
If it loses 2 electrons, it then has eight in the third shell so full and happy, but now there are two more protons than electrons so the charge is +2
see: https://www.khanacademy.org/science/chemistry/chemical-bonds/copy-of-dot-structures/v/drawing-dot-structures
To add to Damon's excellent answer another way to do this is this way and this avoids filling in all those shells with dots. Write the symbol for the element first, then add dots FOR THE OUTER SHELL.
H. would be hydrogen
Ca: would be calcium
Ca^2+ or Ca^++ would be the calcium ion. You will learn more about this when you study Lewis structures, also called Lewis electron dot structures.
To determine where the dot goes on the letter "H" in a Lewis dot structure, we need to know its electron configuration. The dot represents an additional valence electron.
The element "H" is hydrogen, which is located in Group 1 of the periodic table. It has one valence electron in its outermost shell. In a Lewis dot structure, the dot is placed above the letter "H" to represent the valence electron.
Regarding "Ca^2+", the "Ca" represents the element calcium. The superscript "2+" indicates that calcium has lost two electrons, resulting in a 2+ charge.
When writing the electron configuration for an ion with a 2+ charge, we need to consider the number of electrons lost. Calcium normally has 20 electrons, with 2 electrons in its outermost shell. By losing those two outer electrons, the resulting calcium ion (Ca^2+) has a complete stable electron configuration.
To represent the 2+ charge, we write the symbol for calcium (Ca) and then add a superscript "2+" above and to the right of the symbol. So, the correct representation for Ca^2+ would be Ca^2+.