# Question #bc737

Jan 18, 2014

The percent composition of an element is 100 %.

An element is a pure substance. There is nothing else in it.

Assume you have 25.0 g of the element.

% by mass = mass of element/total mass × 100 % =

(25.0 g)/(25.0 g + everything else) × 100% =

$\frac{25.0 g}{25.0 g + 0}$ × 100 % = $\frac{25.0 g}{25.0 g}$ × 100 % = 1.00 × 100 % = 100 %