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jok3333 [9.3K]
2 years ago
7

What percentage of a substance remains after 7 half-lives have passed?

Chemistry
1 answer:
Mila [183]2 years ago
5 0

Answer:

Not really sure, buts its either B or C.

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Liquid sodium is being considered as an engine coolant. How many grams of liquid sodium (minimum) are needed to absorb 1.30 MJ o
Sunny_sXe [5.5K]

Answer:

97 000 g Na

Explanation:

The absortion (or liberation) of energy in form of heat is expressed by:

q=m*Cp*ΔT

The information we have:

q=1.30MJ= 1.30*10^6 J

ΔT = 10.0°C = 10.0 K (ΔT is the same in °C than in K)

Cp=30.8 J/(K mol Na)

If you notice, the Cp in the question is in relation with mol of Na. Before using the q equation, we can find the Cp in relation to the grams of Na.

To do so, we use the molar mass of Na= 22.99g/mol

Cp= \frac{30.8J}{K*mol Na}*\frac{1 mol Na}{22.99 g Na}=1.34\frac{J}{K*g Na}

Now, we are able to solve for m:

m=\frac{1.30*10^6 J}{1.34\frac{J}{K*g Na} *10.0K}=\frac{1.30*10^6J}{13.4\frac{J}{g Na} }  = 9.70*10^4 g Na=97 Kg Na=97 000 g Na

7 0
3 years ago
Read 2 more answers
In the combined gas law, if the volume is decreased, what happens to the temperature if pressure remains constant?
Flura [38]

The correct answer is A. In the combined gas law, if the volume is decreased and the pressure is constant, then the temperature decreases.

 <span>P1V1/ T1 = P2V2 / T2</span>

 <span>Assume the volume decrease by half; V2 = V1/2</span>

 <span>P1V1/ T1 = P2V1 /2 T2</span>

 <span>Cancelling terms,</span>

 <span>1/T1 = 1/2 T2</span>

T2 = T1/2

 <span>Thus, the temperature decreased.</span>

8 0
3 years ago
What are the transition metals
Valentin [98]
Theyre the big bunched up group in the middle of the periodic table
8 0
2 years ago
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In what way are electrons quantized?
KiRa [710]

<u>Answer:</u> The correct option is A) They have fixed energy values.

<u>Explanation:</u>

Electron is one of the sub-atomic particle present around the nucleus of an atom which is negatively charged.

In an atomic model, it is assumed that the electron revolves around the nucleus in discrete orbits having fixed energy levels.

These electrons when jumping from one energy level to another, some amount of radiation is either emitted or absorbed.

These fixed energy levels are given by the Bohr model and thus, the electrons are quantized.

Hence, the correct option is A) They have fixed energy values.

6 0
3 years ago
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The man who developed the concept that light is emitted and absorbed in bundles or packets was:
ludmilkaskok [199]
Planck suggested that light/energy was absorbed/released in certain amounts, called quanta.
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3 years ago
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