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3 years ago

What happens to the intensity of light emitted from stars the further away the star is from us?

1 answer:

6 0

Answer: stars vary in their effective temperature and colour. A hot star radiates more energy per second per metre surface area than a cooler star. Does this then mean that a hot star is going to appear brighter to us than a cooler one? The answer to this actually depends on a few factors

Explanation: pa brainiest po

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Heelp

Alchen [17]

Balanced:
1. Na2O + H2O ---> 2NaOH
2. K2O + H2O ---> 2KOH
3. MgO + H2O ---> Mg(OH)2
4. CaO + H2O ---> Ca(OH)2
5. SO2 + H2O ⇄ H2SO3
6. SO3 + H2O ---> H2SO4
All except by 2 were balanced.

7 0

3 years ago

Which of the following do you pracrice at home

S_A_V [24]

You didn’t post the photo or full question

8 0

3 years ago

in a simulation mercury removal from industrial wastewater, 0.020 L of 0.10 M sodium sulfide reacts with 0.050 L of 0.010 M merc

Margarita [4]

Answer: 0.1161 grams of mercury(II) sulfide) form.

Explanation:

To calculate the number of moles for given molarity, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}\times 1000}{\text{Volume of solution (in L)}}$ .....(1)

a) Molarity of $Na_2S$ solution = 0.10 M

Volume of solution = 0.020 L

Putting values in equation 1, we get:

$0.10M=\frac{\text{Moles of }Na_2S}{0.020L}\\\\\text{Moles of Na_2S}={0.10mol/L\times 0.020}=0.002mol$

$\text {Moles of}Na_2S=0.10M\times 0.020L=0.002mol$

b) Molarity of $Hg(NO_3)_2$ solution = 0.010 M

Volume of solution = 0.050 L

Putting values in equation 1, we get:

$0.010M=\frac{\text{Moles of }Hg(NO_3)_2}{0.050L}\\\\\text{Moles of }Hg(NO_3)_2={0.010mol/L\times 0.050}=0.0005mol$

$Na_2S+Hg(NO_3)_2\rightarrow HgS+2NaNO_3$

According to stoichiometry :

1 mole of $Hg(NO_3)_2$ reacts with 1 mole of $Na_2S$

Thus 0.0005 moles of $HgNO_3$ reacts with= $\frac{1}{1}\times 0.0005=0.0005$ moles of $Hg(NO_3)_2$

Thus $Hg(NO_3)_2$ is the limiting reagent and $Na_2S$ is the excess reagent.

According to stoichiometry :

1 mole of $Hg(NO_3)_2$ forms= 1 mole of $Hg_2S$

Thus 0.0005 moles of $Hg(NO_3)_2$ forms= $\frac{1}{1}\times 0.0005=0.0005$ moles of $Hg_2S$

mass of $H_2S=moles\times {\text {Molar mass}}=0.0005mol\times 232.2g/mol=0.1161g$

Thus 0.1161 grams of mercury(II) sulfide) form.

5 0

3 years ago

PLEASE HELP!!!!!

sergeinik [125]

It gains 2 electrons from a metal

7 0

3 years ago

The reaction CH2CH2 + H2 → CH3CH3 is an example of

Viefleur [7K]

The choices can be found elsewhere and as follows:

(1) substitution
(2) esterification
(3) addition
(4) fermentation

I believe the correct answer is option 3. The reaction CH2CH2 + H2 → CH3CH3 is an example of an addition reaction. It is a reaction where two or more molecules combine to form a larger one. Hope this answers the question.

4 0

4 years ago

Read 2 more answers