Does anyone know the answer to this?

Nobody "knows" the answer, but many people know how to find it,
and there's no reason that you shouldn't be one of them.

Right there, on the screen, it gives you the complete formula to use,
and then it gives you all the numbers to write into the formula. 
All you need to do is write the numbers they gave you into the
formula that they gave you, and do the arithmetic.  There's isn't
even any Physics here !  Just arithmetic, and you can do it with
your calculator.

The formula is          F  =  k · q₁ · q₂  /  r²

The 'q's are  0.0042  and  -0.005 , and 'r' is  0.003 .

Please !  Don't embarrass both of us.
Write the 'q's and the 'r' into the formula, turn the crank,
and match the answer on your calculator to the choices.

Hey hope you get the answer but i suck at math sorry : (

Molybdeum(mo)orruthenium (ru)actually, elements with similar chemical properties as technetium would bemn, re, and bh. this is because elements in the same group/family (column) have similar chemical properties. elements in the same period (row) have the same number of energy levels (or shells).