Are neutrons present in all atoms?

Where are protons present in an atom ?

An atom has mass number A and atomic number Z. How many neutrons are present in its nucleus ?

How many electrons , protons and neutrons are present in Ba2+ having atomic no 56 and atomic mass 137.

If mass of one atom is 3.32 xx 10^(-23)g, then calculate number of nucleons (neutrons and protons) present in 2 atoms of the element:

Calculate number of neutrons present in 12 xx 10^25 atoms of oxygen (8O^17) : (Given : N_A=6 xx 10^23 )

The total number of neutrons present in 54mL H_2O(l) are :

In earthworm, setae are present in all the segments except

How many core electrons are present in potassium. (atomic no = 19 ).

A single electron in an ion has ionization energy equal to 217.6eV . What is the total number of neutrons present in one ion of it?

How many atoms are present in 1 gram atom of an element ?