Part of one row of the periodic table is shown.

Which element's atoms have the greatest average number of neutrons?

tin (Sn)

antimony (Sb)

tellurium (Te)

iodine (I)

tellurium (Te)

Number of neutrons can be calculated as = mass number-atomic number

so for all these elements, no. of neutrons will be calculated as:

For tin (Sn),

number of neutrons = 119-50

=69

For antimony (Sb),

No. of neutrons=122-51

=71

For Tellurium (Te),

No. of neutrons=128-52

=76

For iodine (I),

No. of neutrons = 127-53

= 74

So tellurium will have highest number of neutrons