Consider the nuclear equation below.

Variable X right arrow superscript 228 subscript 89 upper A c plus superscript 0 subscript negative 1 beta.

What is the nuclide symbol of X?
Superscript 230 subscript 90 upper T h.
Superscript 229 subscript 89 upper A c.
Superscript 228 subscript 90 upper T h.
Superscript 238 subscript 88 upper R a.

D. 228/88 Ra

(Photo for proof at the bottom.)

When balancing nuclear equations, the top number (mass number), and the bottom number (atomic number) on each side must be equal in total.

In this example, our answer has a mass number of 228 and atomic number of 88. The mass number of 228 is found from adding the 2 mass numbers on the other side of the equation, 228 and 0. The atomic number of 88 is found from adding the 2 atomic numbers on the other side, 89 and -1.

To identify the element, you look in the periodic table and see which element has the atomic number of 88. In the periodic table, the atomic number is the number at the top of each element.

Here's a photo of Edge, good luck.

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