The elements are identified by its aomic number and they are placed in the periodic table in ascending order of atomic number.
There is one unique element for a given atomic number.
For example, atomic number 1 identifies Hydrogen and there cannot be another different element with the same atomic number.
All the elements with atomic numbers from 1 to 118 have been discovered. So, you know that there is not room for new products with atomic number equal or less than 118.
Answer:
neutral
Explanation:
19+3=22
22 protons & 22 neutrons --> neutral net charge
The answer is A. Most galaxies appear to be moving away from each other. Scientists discovered this when looking through very expensive microscopes, and saw that the universe was always growing and expanding, as if exploding from one point and moving outward.
Answer: the mass number is 51.9961 u.
Explanation: Basically your looking for the mass number of a ATOM of chromium now if you where looking for chromium and not the atom it's self it would be a different number which is 52-54