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fomenos
2 years ago
8

An object in space is made of gas and gives off light and heat energy. We can only see it at night. Which object is it? (2 point

s)
Earth
moon
star
sun
Chemistry
1 answer:
strojnjashka [21]2 years ago
7 0

Answer:

stars

earth isn't made of gas. (and you can always see it)

moon us not gas, or give off heat

sun is only visible during the day

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Suppose an aluminum- nuclide transforms into a phosphorus- nuclide by absorbing an alpha particle and emitting a neutron. Comple
AfilCa [17]

Explanation:

An alpha particles is basically a helium nucleus and it contains 2 protons and 2 neutrons.  

Symbol of an alpha particle is ^{4}_{2}\alpha. Whereas a neutron is represented by a symbol ^{1}_{0}n, that is, it has zero protons and only 1 neutron.

Therefore, reaction equation when an aluminum- nuclide transforms into a phosphorus- nuclide by absorbing an alpha particle and emitting a neutron is as follows.

        ^{27}_{13}Al + ^{1}_{0}n \rightarrow ^{30}_{15}P + ^{1}_{0}n

5 0
3 years ago
One mole of an ideal gas with a volume of 1.0 L and a pressure of 5.0 atm is allowed to expand isothermally into an evacuated bu
Deffense [45]

Answer:

w= - 1.7173 kJ, q= 1.7173 kJ, q(rev) = 1717.3 J = 1.7173 kJ.

Explanation:

Okay, from the question we are given the information below;

Number of moles, n= 1 mole; initial volume, v(1) = 1.0 litres (L); pressure (p) = 5atm, final volume(v2) = 2.0 Litres(L) ; the workdone, w= not given; the heat, q and q(rev)= not given and the gas was said to expand isothermally.

So, this question is a question from the part of chemistry known as thermodynamics. Therefore, grip yourself we are delving into thermodynamics 'waters' now.

For expansion isothermally; the workdone, w= -nRT ln v2/v1.

Where T= temperature= 25° C = 298 k and R= gas constant.

Therefore; workdone, w = - 1 × 8.314 × 298 × ln(2/1).

Workdone,w= - 1717.32204643. =

- 1717.3 Joules (J).

==> Workdone,w= - 1.7173 kJ.

Then, we are to find q. q can be solved by using the first law of thermodynamics, which by mathematical representation is:

∆U= q + w. Where ∆U= change in internal enegy. Since the question is dealing with isothermal expansion, there is this rule that says for an isothermal expansion ∆U = 0.

Hence, 0 =q + [- 1717.3 Joules (J)].

q=1717.3 J = 1.7173 kJ.

Finally, the q(rev) which is= nRT ln (v2/V1).

q(rev) = 1 × 8.314 × 298 ln (2/1).

q(rev) = 1717.3 J = 1.7173 kJ.

PS: please note the negative signs in the workdone and the positive sign in the q(rev).

7 0
3 years ago
The molar ratio of HPO42- to H2PO4- in a solution is 1.4. Calculate the pH of the solution. Phosphoric acid (H3PO4) is a triprot
Bezzdna [24]

Given is the ratio of conjugate base and conjugate acid of phosphoric acid. pH of a substance is the concentration of the hydrogen ions in its solution and higher this concentration lower is the value of pH.

pKa value is a measure of the strength of acid, it is the negative log of acid dissociation constant Ka.

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Mamont248 [21]

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Therefore, when a person graduated from a college with a degree in horticulture then it means he has obtained enough knowledge about how to grow plants, fruits or vegetables in the best way possible.

Thus, Vincent who also graduated in horticulture cannot accurately tell about human psychology.

Hence, we can conclude that the statement this claim may not be accurate because the blog is produced by someone who is not an expert in the field of human psychology.


7 0
3 years ago
Read 2 more answers
QUESTION 10
iris [78.8K]

Answer:

B

Explanation:

Phosphofructokinase-1

6 0
2 years ago
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