Question

a skin cell is between 0.000003 and 0.000004 meter thick. how do you write 0.000003 in scientific notation? how many places does the digit 3 need to shift from the ones place in order to represent 0.00003?

Explanation:

Step1: Recall scientific - notation rule

Scientific notation is of the form $a\times10^{n}$, where $1\leqslant|a|\lt10$ and $n$ is an integer.

Step2: Determine the value of $a$ and $n$ for 0.00003

For the number 0.00003, to get $a$ such that $1\leqslant|a|\lt10$, we move the decimal point 5 places to the right to get $a = 3$. Since we moved the decimal point 5 places to the right, $n=- 5$. So, $0.00003 = 3\times10^{-5}$.
To answer the second - part of the question, we count the number of places the digit 3 needs to shift from the ones place to represent 0.00003. Starting from 3 (in the ones place) and moving to 0.00003, the digit 3 needs to shift 5 places.

Answer:

The scientific notation of 0.00003 is $3\times10^{-5}$. The digit 3 needs to shift 5 places from the ones place to represent 0.00003, so the answer for the multiple - choice part is 5 places.