A student constructs several terrariums to grow plants. Each terrarium is exposed to a different amount of
sunlight each day. In order to determine the ideal
amount of sunlight, which of the following variables
must be held constant?

A. growth rate
B. amount of sunlight received
C. type of plant

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.