Question

what is the mass of 75,000 oxygen molecules? express your answer in scientific notation. mass of one molecule of oxygen = 5.3×10^(-23) gram. the mass of 75,000 molecules of oxygen is grams. (use scientific notation. use the multiplication symbol in the math palette as needed.)

Explanation:

Step1: Identify the given values

Number of molecules = 75000, mass of one oxygen - molecule = $5.3\times10^{-23}$ g

Step2: Calculate the total mass

Total mass = number of molecules×mass of one - molecule. So, total mass = $75000\times(5.3\times10^{-23})$ g.
First, rewrite 75000 as $7.5\times10^{4}$. Then the product is $(7.5\times10^{4})\times(5.3\times10^{-23})$.
Using the rule of exponents $a^{m}\times a^{n}=a^{m + n}$, we have $(7.5\times5.3)\times10^{4+( - 23)}$.
$7.5\times5.3 = 39.75$, and $4+( - 23)=-19$. So the result is $39.75\times10^{-19}$ g.
Rewrite in proper scientific - notation: $3.975\times10^{-18}$ g.

Answer:

$3.975\times10^{-18}$ g