Two isotopes of an element are similar in the following ways:

* Same atomic number (number of protons): This defines the element. Both isotopes have the same number of protons in their nucleus.

* Same chemical properties: Isotopes of an element have the same number of electrons, which determine how they interact chemically. This means they generally exhibit the same reactivity and form the same types of compounds.

* Same position on the periodic table: Both isotopes occupy the same position on the periodic table because they share the same atomic number.

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