Question

16 mark for review of the x atoms in a certain molecule, 45% are carbon. which expression represents the number of carbon atoms in this molecule? a \\( \frac { x } { 0.45 } \\) b 0.45x c x - 0.45 d x + 0.45

Explanation:

Step1: Convert percentage to decimal

To find a percentage of a number, we first convert the percentage to a decimal. \(45\%=\frac{45}{100} = 0.45\).

Step2: Calculate the number of carbon atoms

If there are \(x\) atoms in total and \(45\%\) (or \(0.45\) in decimal form) of them are carbon, we use the formula \( \text{Part}=\text{Percentage (in decimal)}\times\text{Whole}\). So the number of carbon atoms is \(0.45\times x=0.45x\).

Answer:

B. \(0.45x\)