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2 years ago

Please help me thanks so much

Chemistry

1 answer:

Nitella [24]2 years ago

8 0

Answer:

the answer is in the next one I just answered

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State five differences between compound and mixtures in a tabular form

djyliett [7]

Answer:

The differences between compound and mixtures in a tabular form are as follow:

Both are written differently. Plz do write by making table at once.

Hope it help you

4 0

2 years ago

Uranium-235 decays to form lead-207. The half-life of uranium-235 is 704,000,000 years. What is the approximate age of an igneou

Strike441 [17]

Answer:

The approximate age of the igneous rock is $7.042\times 10^{6}$ years.

Explanation:

Chemically speaking, the Uranium-235 decays to form Lead-207 throughout time. All isotopes decay exponentially by means of the following model:

$m(t) = m_{o}\cdot e^{-\frac{t}{\tau} }$ (1)

In addition, we can determine the time constant of the former isotope in terms of its half life, that is:

$\tau = \frac{t_{1/2}}{\ln 2}$ (2)

Where:

$m_{o}$ - Initial mass of Uranium-235, in atoms.

$m(t)$ - Current mass of Uranium-235, in atoms.

$\tau$ - TIme constant, in years.

$t_{1/2}$ - Half-life of Uranium-235, in years.

Please remind that a 1 : 1 ratio of Uranium-235 to Lead-207 atoms means that current mass of Uranium-235 is a half of its initial mass. If we know that $m(t) = 0.5\cdot m_{o}$ and $t_{1/2} = 7.04\times 10^{8}\,yr$ , then the approximate age of the igneous rock is:

$\tau = \frac{7.04\times 10^{8}\,yr}{\ln 2}$

$\tau \approx 1.016\times 10^{9}\,yr$

$t = -\tau \cdot \ln \left(\frac{m(t)}{m_{o}} \right)$

$t = -(1.016\times 10^{9}\,yr)\cdot \ln \frac{1}{2}$

$t \approx 7.042\times 10^{6}\,yr$

The approximate age of the igneous rock is $7.042\times 10^{6}$ years.

5 0

2 years ago

total kinetic energy of all the atoms that make up a sample of matter, would that be heat or mechanical????

Yuki888 [10]

Generally speaking mechanical energy is energy which physically moves (the object), while the thermal energy is energy from the movement of atoms.
Basically temperature is a measurement of atomic movement (doesn't move object as a whole).
Hence heat.

7 0

2 years ago

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______ use energy from their enviornment to make food .

wlad13 [49]

Answer:

autotrophs

Explanation:

3 0

3 years ago

Read 2 more answers

Nitric acid can be produced by the reaction of gaseous nitrogen dioxide with water. 3 no2(g + h2o(? ?? 2 hno3(? + no(g if 538 l

Phantasy [73]

The balanced chemical reaction is written as:

<span>3NO2 + H2O = 2HNO3 + NO

Assuming that the gases in this reaction are ideal gas, then we can use the conversion from L to moles which is 1 mol of ideal gas is equal to 22.4 L. We calculate as follows:

538 L NO2 ( 1 mol / 22.4L ) ( 1 mol NO / 3 mol NO2 ) ( 22.4 L / 1 mol ) = 179.33 L NO is produced</span>

8 0

2 years ago