It has a total of <span>7.4343329e+25 particles
</span>
Answer:
105 mg
Explanation:
The following data were obtained from the question:
Original amount (N₀) = 420 mg
Half life (t½) =20 days
Time (t) = 40 days
Amount remaining (N) =..?
Next, we shall determine the rate constant K, for the disintegration.
This can be obtained as follow:
Half life (t½) =20 days
Rate constant (K) =?
K = 0.693/ t½
K = 0.693/20
K = 0.03465 /day
Finally, we shall determine the amount remaining after 40 days as follow:
Original amount (N₀) = 420 mg
Rate constant (K) = 0.03465 /day
Time (t) = 40 days
Amount remaining (N) =..?
Log(N₀/N) = kt/2.3
Log (420/N) = (0.03465 x 40)/2.3
Log (420/N) = 1.386/2.3
Log (420/N) = 0.6026
420/N = antilog (0.6026)
420/N = 4
Cross multiply
420 = N x 4
Divide both side by 4
N = 420/4
N = 105 mg
Therefore, the amount remaining after 40 days is 105 mg.
Answer:
1) In all energy transformations,kinetic energy changes.
Two metals with equal mass will absorb heat according to their heat absorbing capacity.
The increase in entropy will cause the solid substance to break into multiple pieces.
When these solute particles detach from each other they will form a solution. Entropy increase will cause the temperature to increase.
Decrease in enthalpy is an exothermic reaction which releases heat from the reaction and then desired products will be formed.
Learn more at brainly.com/question/24376442
B. False
Most of the body is made up of <span>oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus, all of which are abundant on Earth.</span>
