Fill in the blanks with correct answers

1) Every square number con be expressed as the sum of two consecutive ________ numbers.
2) Between the square of number n and n+1, there are exactly ________ non-perfect square number.

3) One digit of number is 2 them once digit of square is ________ .

4) Square number and never _________ .

5) [tex]\sqrt{0.25}[/tex]= __________ .