Radioisotopes tell scientists that the earth is how old?

Radioisotopes tell scientists that the earth is 4.5 billion years old.

It is 4.6 billion years i think, hope this helps

Well, both latitude and intensity of light affect temperature because, the higher the light intensity, the higher the temperature and since latitude is the measure of how close you are to the equator, then the closer to the equator you are, the higher the temperature is.