Question

The size of a human hair strand is about 0.12 mm. Express it in the unit of angstrom.

• A. 1200000

Answer 1

The correct option is A 1200000
1 angstrom = ${10}^{-10}m$

1 metre = $1000mm$ = ${10}^{3}mm$

So, 1 angstrom = ${10}^{-10}\times {10}^{3}mm={10}^{-7}mm$

In other words, $1mm={10}^7$ angstrom

Given, the size of a human hair strand = $0.12mm$

$⟹0.12\times {10}^7$ angstrom
$⟹12\times {10}^5$ angstrom
$⟹12,00,000$ angstrom