Why is the atomic radius of sodium more than tellurium?

The atomic radius is the distance from the nucleus of an atom to the outermost electrons. When we move between the groups the outermost shell has been added and hence more electrons are added which make the atom increase its size. read more

It has an atomic radius of 186pm, and therefore a volume of 2.6x10^-29 m^3. Dividing mass by volume gives us a density of 1.3x10^6 g*m^-3. Earth on the other hand, weighs in at 5.97x10^27 grams, and has a volume of 1.09x10^21 m^3. read more

Sodium have 11 electron, which are filled in its shell in order of 2,8,1 so in total three shells on the other hand potassim atomic no. is 19 and so have 19 electrons in its shell in order of 2,8,8,1 i.e. four shells so have bigger size and also more havier then sodium. read more

The atomic radius is the distance from the nucleus of an atom to the outermost electrons. Since the orbitals around an atom are defined in terms of a probability distribution in quantum mechanics, and do not have fixed boundaries, determining where an atom "stops" is not very straightforward. read more