Which process occurs when uranium-235 is bombarded with neutrons to produce smaller nuclei?

An isotope, X, of a particular element has an atomic number of 8 and a mass number of 18. Therefore:

GarryVolchara [31]

Answer:

D

Explanation:

Because the atomic number is 8, we can see that it is indeed an isotope of oxygen. If the mass number is 18, this means that the protons and neutrons added together = 18, so there are 10 neutrons. It does not have an atomic mass of 15.9994 like the element on the periodic table, however, as this is a confirmed isotope and not an average.

4 0

3 years ago

The density of a metal cube is 8 x103 kg/m3. Convert

Rom4ik [11]

Answer:

Explanation:

[peirod4

4 0

3 years ago

The initial reaction rate for the elementary reaction 2A + B → 4C was measured as a function of temperature when the concentrati

Artist 52 [7]

Complete Question

The complete question is shown on the first uploaded image

Answer:

a) The activation energy is 124.776 $\frac{kJ}{mole}$

b) The frequency factor is 1.77 × $10^{18}$

c) The rate constant is 0.00033 $(\frac{dm^{3} }{mole} )^{2}$ $\frac{1}{s}$

Explanation:

From the question the elementary reaction for A and B is given as

2A + B → 4C

The rate equation the elementary reaction is

- $r_{A}$ = $k$ $[A]^{2}$ $[B]$

= $k[2]^{2}[1.5]$

= 6k

$k = \frac{-r_{A} }{6}$

When temperature changes, the rate constant change an this causes the rate of reaction to change as shown on the second uploaded image.

The relationship between temperature and rate constant can be deduced from these equation

$k = Aexp(-\frac{E_{a} }{RT} )$

taking ln of both sides we have

$lnk =ln A - (\frac{E_{a} }{R}) \frac{1}{T}$

Considering the graph for the rate constant $ln k$ and $(\frac{1}{T} )$ the slope from the equation is $-(\frac{E_{a} }{R})$ and the intercept is $ln A$

From the given table we can generate another table using the equation above as shown on the third uploaded image

The graph of $ln k$ vs $(\frac{1}{T} )$ is shown on the fourth uploaded image

From the graph we can see that the slope is $-(\frac{E_{a} }{R} ) = - 15008$

Now we can obtain the activation energy $E_{a}$ by making it the subject in the equation also generally R which is the gas constant is $8.145 \frac{J}{kmole}$

$E_{a} = 15008 × 8,3145\frac{J}{molK}$

$= 124\frac{KJ}{mole}$

Hence the activation energy is $= 124\frac{KJ}{mole}$

b) From the graph its intercept is $ln A = 42.019$

$A = exp(42.019)$

$=1.77 × 10^{18}$

Hence the frquency factor A is $=1.77 × 10^{18}$

c) From the equation of rate constant

$lnk =ln A - (\frac{E_{a} }{R}) \frac{1}{T}$

We have

$ln k = 42.019 - 15008 * (\frac{1}{300} )$

$k = 0.00033(\frac{dm^{3} }{mole} )^{2} \frac{1}{s}$

Hence the rate constant is $k = 0.00033(\frac{dm^{3} }{mole} )^{2} \frac{1}{s}$

6 0

3 years ago

How many moles of sulfuric acid (H2SO4) are needed to react completely with 6.8 moles of lithium hydroxide (LiOH)? (4 points) 2L

Keith_Richards [23]

Answer:

3.4 mol H2SO4

Explanation:

Took the test

3 0

3 years ago

Your teacher lights a small candle and allows it to burn. At first, the candle wax melts, but then it seems to burn away and dis

Margarita [4]

Burning of the candle is both physical and chemical change.burning of the candle causes the candle to melt the wax.so the wax has changed it was solid now it is liquid.the wax combines with the atmospheric oxygen and changes to carbon dioxide,heat and light.thus both the changes are accompanied by the burning of the candle.

3 0

1 year ago

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