Main Body

(about[latex] \ boldsymbol{10^{-9} \ textbf{ m}}[/latex]in diameter)…became (about[latex]boldsymbol{10^{-9}textbf{ m}}[/latex]in diameter)

(about[latex]boldsymbol{10^{-9} textbf{ m}}[/latex]in diameter)…became (about[latex]boldsymbol{10^{-9}textbf{ m}}[/latex]in diameter)