A student is conducting an investigation to determine the identity of an unknown substance. Which of these observations represent physical properties of the substance?

Balance this equation: n2 + h2 > nh3, write the following molar ratios: n2 / n2 / nh3 h2 /

Which of the following true? a_volcanoes and earthquakes often near the plate boundaries. b_volcanoes occur whereve there are tall mountains. c_earthquakes cause volcanoes in the same location to erupt violently d_volcanoes and earthquakes occur only where plates are colliding with each other

What does the process of natural selection involve