Isotopes are atoms of the same element that have the same number of protons but a different number of neutrons. Therefore, isotopes have the same atomic number (number of protons) but a different mass number (number of protons plus number of neutrons). Typically, the mass number is written as a superscript in front of the elemental symbol. Which of the following pairs are isotopes of each otherDetrium and tritiumhydrogen and proton

Deutrium and Tritiumhydrogen

Explanation:They have same number of protons but different neutrons number.

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6

a:

by the combination of an unlimited number of elements