The diameter of a hydrogen atom is about 5×10^-11 meter. Suppose 8.4×10^8 hydrogen atoms were arranged side by side in a straight line. Multiply these numbers to find the length of this line of atoms. What is the length in scientific notation?
42×10^−3 meter
0.042 meter
4.2×10^−2 meter
4.2×10^−3 meter
A hydrogen atom's diameter in metres is
5.3×10
−11
m
.
How many hydrogen atoms could fit in a line of
0.047metres?
To find the length of the line of hydrogen atoms, we need to multiply the diameter of a single atom (5×10^-11 meter) by the number of atoms (8.4×10^8).
Multiplying these numbers, we get:
(5×10^-11 meter) × (8.4×10^8) = (5×8.4) × (10^-11 × 10^8)
= 42 × 10^-3 meter
Therefore, the length of the line of hydrogen atoms is 42×10^-3 meter, which can also be expressed as 4.2×10^-2 meter in scientific notation.
So, the correct answer is 4.2×10^−2 meter.
To find the length of the line of hydrogen atoms, we need to multiply the diameter of a single hydrogen atom by the number of atoms arranged in a straight line.
Diameter of a hydrogen atom = 5×10^-11 meter
Number of hydrogen atoms arranged side by side = 8.4×10^8
To multiply these numbers, we can use the rules of scientific notation:
(5×10^-11) × (8.4×10^8)
When multiplying numbers in scientific notation, we multiply the coefficients and add the exponents:
5 × 8.4 = 42
10^-11 × 10^8 = 10^(-11+8) = 10^-3
Therefore, the length of the line of atoms is 42×10^-3 meters.
However, the options provided are in scientific notation, so we need to convert the answer to scientific notation as well. 42×10^-3 can be written as 4.2×10^-2, which matches the answer choice:
4.2×10^−2 meter
1. 0.042
2. 0.042
3. 0.0042
I have no idea how that works. i used cymath . com to get the answer.
Nice multiplication and minus signs by the way.