[HELP PLEASE !!} Which has a pH below 7?

a
acid
b
base

What happens to energy in an open system?

T(s) in2os] (m) 0 185 2.39 546 1.90 725 1.70 the decomposition of n205 can be described by the equation 2.68 given these data for the reaction at 45°c in carbon tetrachloride solution, calculate the average rate of reaction for each successive time interval. ntr s to 185 s 185 s to 546 s 546 s to 725 s number number number reaction rate: m/s m/s m/s

Can anyone explain 1. review your spectrometry data and use the known elements to identify the star's composition. which unknown elements make up this star? justify your element selections. 2. in parts i and ii of the lab, what happened to the electrons of each element to produce the different colors of light? explain your answers using important terms from the lesson and information provided in the laboratory. 3. stars composed of heavier (more massive) elements are often slightly older than stars made predominantly from hydrogen and helium. based on your data, is the newly discovered star a younger star? explain your answer.