Start by adding the numbers then divide
Minerals physical characteristics are hardness,luster,the way it’s solid and chemical would be the way the color changes and it’s density
Leah's experiment:
A. Takes careful and regular measurements (she measures the growth every day)
B. Has a specific hypothesis and a controlled experiment (the music is the only changing variable, the growth conditions are identical, and this is what she wants to test in her hypothesis)
C. Experimental data that can be recorded and analyzed (measuring the growth of plant fits this)
So the answer must be D, since there is no mention of past research that scientists have found on this topic.
Answer:
Cost to supply enough vanillin is 
Explanation:
Threshold limit of vanillin in air is 
per litre means there should be of vanillin in 1L of air to detect aroma of vanillin.
So, 
So amount of vanillin should be present to detect = 
As cost of 50 g vanillin is 
therefore cost of vanillin = 
Physical change alters a given material without changing its chemical.
