Question

question 2. if z is the symbol for an element, which pair among the following represents isotopes of the same element? 51 z and 50 z, 51 z and 25 z, 50 z and 25 z, 51 z and 26 z, 51 z and 25 z

Explanation:

Step1: Recall isotope definition

Isotopes of the same element have the same atomic number (Z - number of protons) but different mass numbers (sum of protons and neutrons).

Step2: Analyze each option

We need to find the pair where the Z - value (atomic number) is the same.

• For the pair 51 Z and 51 Z with mass numbers 25 and 26 respectively, the atomic number is the same (51), so these are isotopes of the same element.

Answer:

51 Z and 51 Z with mass numbers 25 and 26 respectively (assuming this is one of the options as the text formatting is a bit unclear from the image but the logic is based on same - Z value for isotopes of same element)