The answer is 14.
Hope this helps
Isotopes are chemical elements with same atomic number (Z), but different mass number (different number of neutrons).
Hydrogen is an element with atomic number 1. It has three isotopes:
1) protium (₁¹H), with mass number 1 (no neutrons).
2) deuterium (₁²H), with mass number 2 (one neutrons, n° = 2 -1, n° = 1).
3) tritium (₁³H), with mass number 3 (two neutrons, n° = 3 -1, n° = 2).
speed and direction in which an object is moving. both speed and direction of motion. is a vector. two or more velocities add by velocity addition.
Answer:
they all have two electrons in their outermost shell
