The original mass of krypton 81 that is present in the ice is 6.70 grams.
<h3>How do we calculate original mass?</h3>
Original mass of any substance will be calculated as below for the decomposition reaction is:
N = N₀(1/2)ⁿ, where
N = remaining mass of krypton-81 = 1.675g
N₀ = original mass of krypton-81 = ?
n will be calculated as:
n = T/t, where
T = total time period = 458,000 years
t = half life time = 229,000 years
n = 458,000/229,000 = 2
Now putting all these values on the above equation, we get
N₀ = 1.675 / (1/2)²
N₀ = 6.70 g
Hence required mass is 6.70 g.
To know more about half life time, visit the below link:
brainly.com/question/2320811
Answer:
I would say A
Explanation:
our ancestors are the people that lived long before us
For the answer to the question above asking w<span>hich of the following would likely form a heterogeneous mixture?
The answer would be</span> <span>sand and water
other choices like
,baking soda salt and sugar are soluble in water and form homogeneous solution</span>
First find the number of moles of KSCN is in 4.40g of KSCN
1. Number of moles = mass given (4.40g) / molecular weight(MW) (KSCN)
- to calculate MW, look for each element in the periodic table and add their atomic weight
2. Convert 200mL to liters
3. Concentration = number of moles/ volume in liters from (#2)
