Pls answer this with an explanation if you can

There are 35 seventh-graders in the club

Step-by-step explanation:

4 : 7

20 : ?

20/4=5 so you do this to the other side as well,so 7*5 =35

answer=35

£56

step-by-step explanation:

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: