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3 years ago

Please Help!

1 answer:

3 0

We can use two equations for this problem.

t1/2 = ln 2 / λ = 0.693 / λ
Where t1/2 is the half-life of the element and λ is decay constant.

20 days = 0.693 / λ
λ = 0.693 / 20 days (1)

Nt = Nο eΛ(-λt) (2)

Where Nt is atoms at t time, No is the initial amount of substance, λ is decay constant and t is the time taken.
t = 40 days

No = 200 g

From (1) and (2),
Nt = 200 g eΛ(-(0.693 / 20 days) 40 days)
Nt = 50.01 g

Hence, 50.01 grams of isotope will remain after 40 days.

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Answer:

4HCl(g) + O₂(g) → 2Cl₂(g) + 2H₂O(g)

Explanation:

In order to find the equation we should state:

The reactants → Hydrogen chloride (HCl) and oxygen (O₂)

The products → Chlorine gas (Cl₂) and water gas (H₂O)

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3 years ago

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How many 3-liter balloons could the 12-L helium tank pressurized to 160 atm fill? Keep in mind that an "exhausted" helium tank i

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Answer:

The 12L helium tank pressurized to 160 atm will fill 636 3-liter balloons

Explanation:

It is possible to answer this question using Boyle's law:

$P_1V_1=P_2V_2$

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160atm×12L = 1atm×V₂

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As the tank will never be empty, the volume of the gas able to fill balloons is the total volume minus 12L, thus the volume of helium able to fill balloons is:

1920L - 12L = 1908L

1908L will fill:

1908L× $\frac{1balloon}{3L}$ = 636 balloons

I hope it helps!

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3 years ago

How many atoms are in 20.6 moles of curium

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Answer: 1.24 × 10^25

Explanation:

$\frac{20.6 moles}{1}$ × $\frac{6.022 * 10^{24} }{1 Mole}$

Using our knowledge in unit conversions, we know the mole units cancel each other out and all there's left is the atom unit. From here we can multiply the fractions and eventually we end with the number 124.0532 × 10^23

According to the scientific notation rules, the number to the left of the decimal cannot exceed 10 so we have to move the decimal to the left two spaces. With this change, we also have to change the exponent of the 10. Because we moved the decimal point two spaces to the left, that means we have 10^25.

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3 years ago

If 3.89 × 1024 atoms of a noble gas is collected and it has a mass of of 848 grams, this element is most likely a. He b. Ne c. A

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Answer:

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