Question

use the periodic table to answer the question. write the atomic symbol (including the atomic number) for the isotope of neodymium with 90 neutrons. write the answer in the form $_z^a x$ using the atomic symbol button in the toolbar, where $a$ is the mass number, $z$ is the atomic number, and $x$ is the chemical symbol for the unknown element.

Explanation:

Step1: Find neodymium's atomic number

From the periodic table, neodymium (Nd) has an atomic number $Z = 60$.

Step2: Calculate the mass number

The mass number $A$ is the sum of protons and neutrons. Protons equal the atomic number. Given 90 neutrons and 60 protons, $A=60 + 90=150$.

Answer:

$_{60}^{150}\text{Nd}$