Answer:
20 neutrons
Explanation:
neutrons = mass number - atomic number
mass number = 39, atomic number = 19
neutrons = 39 - 19 = 20
The metal ion in an ionic compound will loose an electron becoming a cation. It will therefore develop a positive charge. The magnitude of the charge depends on the number of electrons lost. If one electron is lost the ion gains a +1 charge and of 2 is lost it gains a +2 charge ect.
Answer:
South American
Explanation:
When you look at a map of plates, only South American forms a boundary with the African plate out of those specific plates
Waves interact with matter in several ways. The interactions occur when waves pass from one medium to another. Besides bouncing back like an echo, waves may bend or spread out when they strike a new medium. These three ways that waves may interact with matter are called reflection, refraction, and diffraction.
