Answer: a) 3.85 days
b) 10.54 days
Explanation:-
Expression for rate law for first order kinetics is given by:
where,
k = rate constant = ?
t = time taken for decomposition = 3 days
a = let initial amount of the reactant = 100 g
a - x = amount left after decay process = 
First we have to calculate the rate constant, we use the formula :
Now put all the given values in above equation, we get
a) Half-life of radon-222:
Thus half-life of radon-222 is 3.85 days.
b) Time taken for the sample to decay to 15% of its original amount:
where,
k = rate constant = 
t = time taken for decomposition = ?
a = let initial amount of the reactant = 100 g
a - x = amount left after decay process = 
Thus it will take 10.54 days for the sample to decay to 15% of its original amount.
Answer:
When elements bond together or when bonds of compounds are broken and form a new substance
Explanation:
I think the correct answer from the choices listed above is the second option. The relationship between the direction of energy and wave motion in a transverse wave would be the <span>energy direction is perpendicular to the motion of the wave. Hope this answers the question. Have a nice day.</span>
When salt is added, it makes it harder for the water molecules to escape from the pot and enter the gas phase, which happens when water boils, Giddings said. This gives salt water a higher boiling point, she said.
<span>93.3°C
A temperature in Fahrenheit (°F) can be converted to Celsius (°C), using the formula
[°C] = ([°F] − 32) × 5⁄9. Here we have to convert a temperature of 200°F in to Celsius. Thus Subtract 32 from Fahrenheit and multiply by 5 then divide by 9 .
That is (200°F - 32) × 5/9=168 × 5/9
=840/9
=93.333333333°C
= 93.3°C</span>
