The half life equation is -->P(t) = Pi (0.5) ^ (t/c)
c is equal to the element to reach its half-life (5 seconds)t is equal to the duration of time the element is expose to (20 seconds)Pi is the initial amount (340)0.5 is the base of this exponential function to represent half-life.P(t) is the expression for the function of time
P(20) = 340 (0.5)^20/5P(20) = 340 (0.5) ^4P(20)= 21.25 grams
Fraction = P(t)/Pi = P(20)/Pi =21.25/340 =1/16
Therefore, when given 20 seconds, 340 grams of Fluorine-21 will degrade to 21.25 grams OR 1/16 of its original mass.
Hope this method helps! (This is my answer btw, I think you may have accidentally posted twice?)
Answer:
Postassium bisulphate - KHSO4 - can be used as an food preservative to protect the food from micro-organisms.
Answer: CaSO3
Explanation:Please see attachment for explanation
Answer:
1 mole of molecules = 6.022 × 10²³ molecules
1 = 6.022 × 10²³ molecules / mole
Multiplying a number with [6.022 × 10²³ molecules / mole] is like multiplying the number with 1 so 0.877 mole × 6.022 × 10²³ molecules / mole = 5.28 × 10²³ molecules
5.28 × 10²³ molecules of water is produced.
Explanation:
Answer:
The amount of heat that is released is -925.2 cal
Explanation:
Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.
Sensible heat is the amount of heat that a body can receive or release without affecting its molecular structure, that is, it does not change the state (solid, liquid, gaseous). In other words, sensible heat is the amount of heat that a body absorbs or releases without any changes in its physical state.
The equation that allows to calculate heat exchanges is:
Q = c * m * ΔT
Where Q is the heat exchanged by a body of mass m, constituted by a substance of specific heat c and where ΔT is the variation in temperature.
In this case:
- c= 1

- m= 25.7 g
- ΔT= Tfinal - Tinitial= 49 °C - 85 °C= -36 °C
Replacing:
Q= 1
*25.7 g* (-36 C)
Solving:
Q= -925.2 cal
<u><em>The amount of heat that is released is -925.2 cal</em></u>