How do you express the scales for the drawings without units?

explanation:

infrared radiation has wavelength in the range between 700 nm and 1 mm. lets' convert these values into scientific notation, keeping in mind that:

let's start from the lower value, we have:

(we moved the dot two places to the left, so we increased the exponent by 2 units, from -9 to -7)

the higher value is:

so, the range of wavelength of infrared radiation is:

its four gallons, i took the test and this was right.

step-by-step explanation:

on the dot where it starts for four gallons, that's when it doesn't move up any more.