Question

The diameter of the planet Mercury is
4.87 x 103 km. The diameter of the planet Venus is 1.21 x 104 km. The diameter of Earth is 1.28 x 104 km. The diameter of Mars is 6.79 x 103km.
Which planet has the smallest diameter?

Answer 1

To determine which planet has the smallest diameter, we will compare the given diameters:

- Mercury: \(4.87 \times 10^3\) km
- Mars: \(6.79 \times 10^3\) km
- Venus: \(1.21 \times 10^4\) km
- Earth: \(1.28 \times 10^4\) km

Converting the diameters to the same exponent (scientific notation with the same power of 10) can make comparison easier:

- Mercury: \(4.87 \times 10^3\) km
- Mars: \(6.79 \times 10^3\) km
- Venus: \(12.1 \times 10^3\) km (since \(1.21 \times 10^4\) is the same as \(12.1 \times 10^3\) km)
- Earth: \(12.8 \times 10^3\) km (since \(1.28 \times 10^4\) is the same as \(12.8 \times 10^3\) km)

Now we can compare the coefficients (the numbers in front of the powers of 10):

- Mercury: \(4.87\)
- Mars: \(6.79\)
- Venus: \(12.1\)
- Earth: \(12.8\)

From these values, we can see that:

- Mercury (4.87) has the smallest value.

Thus, the planet with the smallest diameter is **Mercury**.