Answer:
A) 277 million years
Step-by-step explanation:
Here, decay of U-238 is first order reaction. (since most of the nuclear decays are first order).
so, the equation t =
× ln(
)
where, t = time from start of reaction
k = reaction constant
A(0) = initial concentration; A = present concentration.
⇒ 4.5 billion = 4500 million years =
× ln2.
Now, given 95.82% of parent U-238 isotope is left.
⇒ t =
× ln(
)
t =
× ln(
)
⇒ t ≅ 277 million years.
Answer:
B
Step-by-step explanation:
Its the only one that makes sense
D- (-2,3) :)
hope that helps
a and b are the two leg sides
c is the longest side.
a^2+b^2=c^2
a=x
b=9
c=11
a=c-b
11 squared is 121
9 squared is 81
121-81=40
The square root of 40, rounded to the nearest hundredth, is 6.32
Answer:
I think it is 0,2
Step-by-step explanation:
Because you need to substitute the ordered pairs into the linear equation:
so,
2(0)+3(2) = 6
6=6
The two side, so equation are identical, so the correct answer is (0,2).
I hope this helps!