Answer:
Explanation:
Iodine - 125
The atomic symbol of iodine is ¹²⁵₅₃ I
The symbol for iodine is I
The atomic number of iodine is 53,
and the atomic mass of iodine is 125 .
<u>The representation of the atomic symbol is as, the atomic mass is written in uppercase and the atomic number is written in lower case , followed by the symbol of the element .</u>
Iodine is a radio active element , used for many biological process .
It is the second largest -lived radioisotope of iodine .
The first is iodine-129 .
Copper has 29 protons, when dealing with Cu^2+ all that means is it lost two electrons. so now the element has 29 protons and 27 electrons. Protons are positive and electrons are negative and neutrons are neutral. So say you had an element X^2- then you have gained two more electrons so the element has an overall negative charge. hope that helps
Answer: The layers are ordered by density, with the least dense layer on top, and the densest layer on the bottom.
Explanation:
Plato
Answer:
1) The elements have filled valence levels.
Explanation:
Since they have filled valence levels, they're stable and don't need to electrons to fill their valence shells since they're already full.
2) False, They do have electrons
3) False, He does have only one electron shell, but going down the periods, every next element have one more electron shell than a preceding one has.
4)False, they're actually the smallest atoms of their respective period
