Q1. The answer is 3 minutes.
Let's first calculate the remaining amount in percent:
If 960g is 100 percent (starting amount), 30 g is how many percents:
960 g : 100% = 30 g : x
x = 30 g * 100% / 960 g = 3.125% = 0.03125
Now, using the formula to calculate the number of half-lives:
(1/2)ⁿ = x,
where
x is the remaining amount: x = 0.03125
n is the number of half-lives
1/2 stands for half-life.
(1/2)ⁿ = 0.03125
⇒ n*log(1/2) = log(0.03125)
n = log(0.03125)/log(1/2) = log(0.03125)/log(0.5) = -1.505/-0.301 ≈ 5
The number of half-lives is 5.
Now, <span>the number of half-lives (n) is a quotient of total time elapsed (T) and length of half-life (L):
n = T/L
We know:
n = 5
T = 15 min
L = ?
Thus
L = T/n
L = 15 min/5 = 3 minutes
Q2. Filtration should be chosen.
Filtration and distillation are used to separate mixtures - filtration for the separation of heterogeneous mixtures and </span>distillation for the separation of homogeneous mixtures. Imagine that your pile of soil is a mixture. It consists of different components (the leaves, acorns, twigs), so it is the heterogeneous mixture. Therefore, to separate the leaves, acorns, twigs you will use filtration.
Answer:
C 108
Explanation:
1 It was found that 4n atoms of metal x
weigh 501.6 g. The relative atomic mass
of X is 209. If n atoms of another metal,
Y, weigh 65.00 g, what is the relative
atomic mass of metal Y?
A 27 B 52 C 108 D 137
if 4n atoms of x weigh 501.6 gm, the n atoms weigh 501.6/4 = 125.4 gms
since the atomic mass is 209, then 6.022 X10^23 atom weigh 209
the ratio of 125.4 to 209 is
125.4/Y =0.6
therefor n is the number of atom in 0.6 moles
if metal Y has the same, number of atoms "n" and weighs 65 gm
then then the relative atomic mass is
65/0.6 =108
so the answer is
C 108
Answer:
36.36
Explanation:
Multiply pressure value by 101 for every problem like this.
