Answer:
47.5 mL
Solving:
M1 = 4.00 M
V1 = ?
M2 = 0.760 M
V2 = 0.250 L
---
M1 * V1 = M2 * V2
V1 = ( M2 * V2 ) / M1
V1 = ( 0.760 * 0.250 ) / 4.00
V1 = ( 0.190 ) / 4.00
V1 = 0.0475 L
Answer:
₈₆²²²Rn → ₈₄Po²¹⁸ + H₂⁴
Explanation:
The given nuclear reaction shows alpha decay.
₈₆²²²Rn → ₈₄Po²¹⁸ + H₂⁴
Properties of alpha radiations:
Alpha radiations are emitted as a result of radioactive decay. The atom emit the alpha particles consist of two proton and two neutrons. Which is also called helium nuclei. When atom undergoes the alpha emission the original atom convert into the atom having mass number less than 4 and atomic number less than 2 as compared to parent atom the starting atom.
Alpha radiations can travel in a short distance.
These radiations can not penetrate into the skin or clothes.
These radiations can be harmful for the human if these are inhaled.
These radiations can be stopped by a piece of paper.
₉₂U²³⁸ → ₉₀Th²³⁴ + ₂He⁴ + energy
Answer:
The new volume of a gas at 750 mmhg and with a volume of 2. 00 l when allowed to change its volume at constant temperature until the pressure is 600 mmhg is 2.5 Liters.
Explanation:
Boyle's law states that the pressure of a given amount of gas is inversely proportional to it's volume at constant temperature. It is written as;
P ∝ V
P V = K
P1 V1 = P2 V2
Parameters :
P1 = Initial pressure of the gas = 750 mmHg
V1 = Initial pressure of the gas = 2. 00 Liters
P2 = Final pressure of the gas = 600 mmHg
V2 = Fimal volume of the gas = ? Liters
Calculations :
V2 = P1 V1 ÷ P2
V2= 750 × 2. 00 ÷ 600
V2 = 1500 ÷ 600
V2 = 2.5 Liters.
Therefore, the new volume of the gas is 2. 5 Liters.
Consider the acid spill. It is already starting to do nasty things to, say, the floor or counter. So you grab the bottle of 10% NaOH and pour some on the spill. All of a sudden, you get a great deal of heat, and you don't have any visual evidence whether your put on too little or too much. But you have added more liquid to the spill, generated more heat, and will get more damage. You have made a bigger mess, and if you added too much, you then have a neutralization problem to deal with.
And if it is something like a strong sulfuric acid solution, adding sodium hydroxide solution will be extremely exothermic, and you could get some really nasty results.
So now approach the spill with a handful of baking soda. You sprinkle it on the spill. It fizzes, and carbon dioxide is given off. That actually, in a very tiny way, moderates the temperature of the neutralization. And you can keep adding baking soda until the fizzing stops, and then perhaps some water to mix everything well. But what you have done is kept the volume to a minimum, added a neutralization agent that has a visible endpoint (no more gas being given off), and you don't suddenly have a huge amount of highly basic solution because you added too much.
And what is also nice about baking soda is that you can toss some with your hand or even with a spoon, and get some distance from the spill. With a liquid, you have to get much closer
i hope this helped..
Answer:
Half-life = 3 minutes
Explanation:
Using the radioactive decay equation we can solve for reaction constant, k. And by using:
K = ln2 / Half-life
We can find half-life of polonium-218
Radioactive decay:
Ln[A] = -kt + ln [A]₀
Where:
[A] could be taken as mass of polonium after t time: 1.0mg
k is Reaction constant, our incognite
t are 12 min
[A]₀ initial amount of polonium-218: 16mg
Ln[A] = -kt + ln [A]₀
Ln[1.0mg] = -k*12min + ln [16mg]
-2.7726 = - k*12min
k = 0.231min⁻¹
Half-life = ln 2 / 0.231min⁻¹
<h3>Half-life = 3 minutes</h3>
