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:
1/9
Step-by-step explanation:
0.1(repeating)
Answer:
<em>Parallel</em>
Step-by-step explanation:
The dotted lines are parallel because they have the same <u>gradient</u> to each other, this means the two dotted lines will <u>never</u> touch each other.
Have a great day <3
Answer:
<em>Riko is wrong because she uses the wrong formula.</em>
Step-by-step explanation:
Given the coordinate points (-2, -3) and (2, -5)
We are to find the distance between the two points
Using the formula:
D = √(x2-x1)²+(y2-y1)²
From the coordinates x1 = -2, y1 = -3, x2 = 2 and y2 = -5
Substitute
D = √(2-(-2))²+(-5-(-3))²
D= √(4)²+(-2)²
D = √16 + 4
D = √20
D = √4*√5
D = 2√5
<em>This shows that Riko is wrong because she uses the wrong formula.</em>