136,56 ba+2 equals how many nuetrons

When a comet collides with earth, it adds material to our planet and causes great damage. therefore, a collision like this is a a. destructive force b. constructive force c. geologic process and event d. constructive and destructive force

Embryos of different species look very similar, which shows that the organisms share a ancestor.

The difference between the atomic number of an element and the element’s atomic mass is the number of ions.