Answer:
pt1
The half-life of the element is 1,600 years.
pt2
k = ln(2)/(t1/2) = 0.693/(t1/2).
Where, k is the rate constant of the reaction.
t1/2 is the half-life of the reaction.
∴ k =0.693/(t1/2) = 0.693/(1,600 years) = 4.33 x 10⁻⁴ year⁻¹.
kt = ln([A₀]/[A]),
where, k is the rate constant of the reaction (k = 4.33 x 10⁻⁴ year⁻¹).
t is the time of the reaction (t = ??? year).
[A₀] is the initial concentration of the sample ([A₀] = 312.0 g).
[A] is the remaining concentration of the sample ([A] = 9.75 g).
∴ t = (1/k) ln([A₀]/[A]) = (1/4.33 x 10⁻⁴ year⁻¹) ln(312.0 g/9.75 g) = [8,000 year].
-Hops
Put the marked magnet up to each side of the unmarked one. if they attract they are opposite -north attracts south, south attracts north- if they repel -forcefully push away- from each other they are the same -north and north, or south and south. once you have done that you can label the poles correctly.
Answer:
1.52
Explanation:
speed of light through clear rock salt = speed of light in air (vacuum)/index of refraction
index of refraction of clear rock salt = speed of light in air (vacuum) / speed of light through clear rock salt
index of refraction of clear rock salt= 3.00 x 10^8 m/s / 1.98 × 10^8 m/s
index of refraction of clear rock salt= 3.00 x 10^8/1.98 × 10^8 ( the × 10^8 cancels out)
index of refraction of clear rock salt= 3.00/1.98
index of refraction of clear rock salt= 1.52
