Answer: 693 years
Step-by-step explanation:
Expression for rate law for first order kinetics is given by:

k = rate constant
t = time taken for decomposition = 1
= Initial amount of the reactant
= amount of the reactant left =



for half life : 

Putting in the values , we get


Thus half life of this isotope, to the nearest year is 693.
Answer:
(-1,-4)
Step-by-step explanation:
Because it is a rotation that turns both the x and y values the two swap places. The x value become negative because before it was in quadrant 4 where there was still a positive chance but rotating the point clockwise puts it into the third quadrant where there are only negatives.
I believe it’s x=2.5 or x=2 1/2 or x=5/2
They are all the same answers in different forms . Hope it’s right
Sum of two numbers is 62?
Let's call the two numbers

and

let's find two same numbers that would add up to 62: 31.
31 + 31 = 62
since it said the difference is 8, we have to add 4 to one number and subtract 4 from another.
31 - 4 = 27
31 + 4 = 35
Therefore, the two numbers following the given rules are 27 and 35