Earth's dynamic processes allow our plant to recycle:

In which situation has the independent variable for the experiment been changed? check all that apply. changed from counting the number of duckweed at day 0 and day 14 to counting them every day changed from testing duckweed growth in beakers to testing duckweed growth in large outdoor tanks changed from testing the effect of ph on duckweed growth to testing the effect of light levels on duckweed growth changed from testing the effect of acid ph on duckweed growth to testing the effect of basic ph on duckweed growth

What are similarities and differences between refraction, reflection, diffraction and absorption?

Which is the correct symbol for an isotope of iodine with 53 protons and 78 neutrons?