已知等差数列\(\{{{a}_{n}}\}\)中,公差\(d\ne 0\),\({{S}_{7}}=35\),且\({{a}_{2}}\),\({{a}_{5}}\),\({{a}_{11}}\)成等比数列.
\((1)\)求数列\(\{{{a}_{n}}\}\)的通项公式;
\((2)\)若\({{T}_{n}}\)为数列\(\{\dfrac{1}{{{a}_{n}}{{a}_{n+1}}}\}\)的前\(n\)项和,且存在\(n\in {{\mathrm{N}}^{*}}\),使得\({{T}_{n}}-\lambda {{a}_{n+1}}\geqslant 0\)成立,求实数\(\lambda \)的取值范围.