Question

What atom is 10ne20​

Answer 1

$^{20}_{10}\text{Ne}$.

That's a neon-20 atom.

Explanation

Here's the symbol of neon-20, showing both its atomic number and its mass number.

$^{20}_{10}\text{Ne}$.

• Ne is the chemical symbol of neon.
• The number 20 in the upper-left corner is the mass number of this atom.
• The number 10 in the lower-left corner is the atomic number of this atom.

How to name this atom?

• Start with the name of the element: "neon" for Ne, atomic number 10.
• Write a hyphen: "-" with no space around.
• Write the mass number: "20" right next to the hyphen.

What about the atomic number? The atomic number is unique for each element. It is implied in the first part of the name. For example, the atomic number of a "neon-20" atom is always going to be 10 since the atomic number of neon is 10. That number is printed on the periodic table. However, the mass number may vary between isotopes of each element. That number needs to be specified.

The name of this atom is neon-20.