Question

What is the symbol of the species with the number of electrons equal to 36 protons equal to 35 and neutrons equal to 45?

Answer 1

The number of protons in the nucleus of every atom of a chemical element is known as the atomic number or proton number (symbol Z). A chemical element's atomic number is the only way to identify it. It is the same as the nucleus' charge number. The atomic number is also equivalent to the number of electrons in an uncharged atom.

Complete answer:
The mass number A of an atom is calculated by adding the atomic number Z and the number of neutrons N. Because protons and neutrons have nearly the same mass (and the mass of electrons is negligible for many purposes), and the mass defect of nucleon binding is always small compared to the nucleon mass, any atom's atomic mass, when expressed in unified atomic mass units (creating a quantity called "relative isotopic mass"), is within 1% of the whole number A.
Bromine is an atomic number 35 chemical element with the symbol Br. It's the third-lightest halogen, and at room temperature, it's a seething red-brown liquid that quickly evaporates to create a similar-colored vapour. It has characteristics that are halfway between chlorine and iodine.
Number of protons Equals atomic number = 35
35+45=80 atomic mass
Hence the species $_{35}B{r^{80}}$
Because the number of electrons is one higher than the number of protons, the given species has a negative charge.$B{r^ - }$is the symbol.(bromide ion)

Note:
Bromine is a highly reactive element that only occurs in nature as colourless soluble crystalline mineral halide salts, similar to table salt. The great solubility of the bromide ion ($B{r^ - }$) has led to its buildup in the seas, despite its rarity in the Earth's crust. The element is easily mined commercially from brine pools, which are primarily found in the United States, Israel, and China. Bromine makes up roughly one-third of the mass of chlorine in the seas.