Write the isotope notation for an element with 53 protons and 20 neutron?

The isotope notation : ⁷³₅₃X

Given

53 protons and 20 neutron

Required

The isotope notation

Solution

Isotopes are elements that have the same atomic number with a different mass number

The following element notation,

X = symbol of element

A = mass number

   = number of protons + number of neutrons

Z = atomic number

   = number of protons = number of electrons, on neutral elements

So the mass number of element = 53 + 20 = 73

Atomic number = 53

The symbol :

the correct answer would be d. hope this !

metals are good conductor of electricity. it has free electrons on their surface. according to electron pool theory, each atom present in a metal crystal losses all of its valence electron and as a result a pool of free is form. these pool of electrons are free to move and   conduct electricity easily   while making metal as good conductor.

the correct answer is a. the ability of electrons to flow throughout the metal.

if it's not useful, feel free to report for mistake in answer.