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3 years ago

what is the half life of a radioactive isotope that decreased to one-fourth its original amount in 100 year

Physics

1 answer:

hichkok12 [17]3 years ago

3 0

Two times 100 years = 200 years is half life

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Automobile air bags use the decomposition of sodium azide as their sources of gas for rapid inflation, represented in the reacti

NeTakaya

Answer : The mass of $NaN_3$ required is 71.175 grams.

Explanation :

To calculate the moles of nitrogen gas, we use the equation given by ideal gas :

PV = nRT

where,

P = Pressure of nitrogen gas = 763 torr

V = Volume of the nitrogen gas = 40.0 L

n = number of moles of gas = ?

R = Gas constant = $62.364\text{ L.torr }mol^{-1}K^{-1}$

T = Temperature of helium gas = $25^oC=273+25=298K$

Putting values in above equation, we get:

$763torr\times 40.0L=n\times 62.364\text{ L.torr }mol^{-1}K^{-1}\times 298K\\\\n=1.642mol$

Now we have to calculate the moles of $NaN_3$ .

The balanced chemical reaction is:

$2NaN_3(s)\rightarrow 2Na(s)+3N_2(g)$

From the balanced chemical reaction, we conclude that

As, 3 moles of $N_2$ produced from 2 moles $NaN_3$

So, 1.642 moles of $N_2$ produced from $\frac{2}{3}\times 1.642=1.095$ moles $NaN_3$

Now we have to calculate the mass of $NaN_3$ .

Molar mass of $NaN_3$ = 65 g/mol

$\text{Mass of }NaN_3=\text{Moles of }NaN_3\times \text{Molar mass of }NaN_3$

$\text{Mass of }NaN_3=1.095mole\times 65g/mole=71.175g$

Therefore, the mass of $NaN_3$ required is 71.175 grams.

5 0

3 years ago

Hello!

Montano1993 [528]

It is true that the light is 15.000 more dangerous than the radiation of a microwave.

<h3>What is the wavelength?</h3>

The wavelength shows the extent or how far the wave travels. Now we know that the energy of the wave can be use to find out how much dangerous the wave is.

Now;

1.6 * 10^-19 J = 1eV

x J = 1.8 eV

x = 1.8 eV * 1.6 * 10^-19 J /1eV

x = 2.88 * 10^-19 J

Now if the energy of the microwaves is 1.2 x 10^-4 J, then it follows that;

2.88 * 10^-19 J/ 1.2 x 10^-4 J,

= 2.4 * 10^15

Hence, it is true that the light is 15.000 more dangerous than the radiation of a microwave.

Learn more about microwave:brainly.com/question/15708046

#SPJ1

5 0

2 years ago

Research indicates that inattentional blindness often decreases when people work on tasks that require a great deal of attention

QveST [7]

The correct answer is F

6 0

3 years ago

Read 2 more answers

A wave is traveling at 241 m/s. It has a wavelength of 30.0 m. What is its frequency?

Feliz [49]

Answer:

A) 8.03Hz

Explanation:

f = V/λ

Where wavelength( λ )= 30m

Speed (V) =241m/S

f= 241/30=8.03Hz

3 0

3 years ago

Which uses motion of water in nature to produce electricity?

Zinaida [17]

Answer: D. Hydroelectric power

Explanation: Hydroelectric means water power (not exactly but "hydro" is water and electric is well self explanatory)

6 0

3 years ago