Express in scientific notation. Make sure your answer has the same number of significant figures as the starting value.
(1.8 x 10-2) ÷ (9 x 102) = _____
2 x 10-5
2.0 x 10-5
0.2 x 10-4
1.8*10^-2/9*10^2 = 0.2*10^-4 = 2.0*10^-5
2x10-5
To express the given expression in scientific notation, let's begin by performing the division:
(1.8 x 10^(-2)) ÷ (9 x 10^(2))
To divide two numbers written in scientific notation, we subtract the exponents and divide the coefficients. So, in this case:
(1.8 ÷ 9) x 10^(-2-2)
0.2 x 10^(-4)
Now, according to the rule of scientific notation, we should write the coefficient as a decimal between 1 and 10 (inclusive) and adjust the exponent accordingly:
0.2 x 10^(-4)
However, notice that there is an extra significant figure in the coefficient (0.2) compared to the original value (1.8 x 10^(-2)). To maintain the same number of significant figures, we need to round the coefficient to one decimal place:
0.2 x 10^(-4) rounded to one significant figure is 2 x 10^(-5)
Therefore, the answer expressed in scientific notation with the same number of significant figures as the starting value is:
2 x 10^(-5)