An exponential decay law has the general form: A = Ao * e ^ (-kt) =>
A/Ao = e^(-kt)
Half-life time => A/Ao = 1/2, and t = 4.5 min
=> 1/2 = e^(-k*4.5) => ln(2) = 4.5k => k = ln(2) / 4.5 ≈ 0.154
Now replace the value of k, Ao = 28g and t = 7 min to find how many grams of Thalium-207 will remain:
A = Ao e ^ (-kt) = 28 g * e ^( -0.154 * 7) = 9.5 g
Answer 9.5 g.
The unit is the Kelvin, but most of the time 273 is subtracted from the Kelvin temperature and the new number is called "degrees Celsius".
Answer:
<u>It increases by a factor of four</u>
Explanation:
Boyle's Law : At constant temperature , the volume of fixed mass of a gas is inversely proportional to its pressure.
pV = K.......(1)
pV = constant
Charles law : The volume of the gas is directly proportional to temperature at constant pressure.
V = KT
or V/T = K = constant ....(2)
Applying equation (1) and (2)


According to question ,
T2 = 4 (T1)
V2 = V1
Put the value of T2 and V2 , The P2 can be calculated,

V1 and V1 cancel each other
T1 and T1 cancel each other
We get,

or
P2 = 4 P1
So pressure increased by the factor of four
Answer:
1.12 × 10⁻⁴ M
Explanation:
Step 1: Write the reaction for the solution of Mg(OH)₂
Mg(OH)₂(s) ⇄ Mg²⁺(aq) + 2 OH⁻(aq)
Step 2: Make an ICE chart
We can relate the solubility product constant (Ksp) with the solubility (S) through an ICE chart.
Mg(OH)₂(s) ⇄ Mg²⁺(aq) + 2 OH⁻(aq)
I 0 0
C +S +2S
E S 2S
The solubility product constant is:
Ksp = 5.61 × 10⁻¹² = [Mg²⁺] × [OH⁻]² = S × (2S)² = 4S³
S = 1.12 × 10⁻⁴ M