Since the sample size is below 30, in this case we use
the t statistic. The formula for t score is:
t = (x – u) / (σ / sqrt n)
where,
x = the level l = unknown
u = sample mean = 120 mg / dl
σ = standard deviation = 20 mg / dl
n = sample size or number of results = 5
Using the standard distribution tables for t, we can find
the value of t given the probability (P = 0.15) and degrees of freedom (DOF).
t = 1.036
Going back to the
formula for t score:
1.036 = (x – 120)
/ (20 / sqrt 5)
x = 129.27 mg /
dl = l
It may seem remarkable that we can learn about the composition of distant stars by studying the light they emit. In fact, we can learn a great deal, not only about the chemical elements present, but also about physical conditions. The key is to spread the light out by color, producing a spectrum like the one shown in Fig. 1. This lab explores some of the basic ideas used to analyze spectra.
An oxygen atom is 16x more massive than a hydrogen atom.
You can figure this out by comparing the atomic masses of the two elements: oxygen has an atomic mass number of 16, and hydrogen has an atomic mass number of 1. Thus, an oxygen atom is 16 times more massive than a hydrogen atom.
Answer:
Aluminum
Explanation:
I just used the Reactivity Series chart :)