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AURORKA [14]
4 years ago
7

Atoms are incredibly small and we cannot see them, even with very powerful microscopes. If we cannot see them, then how do we kn

ow they are there?
Chemistry
1 answer:
Alekssandra [29.7K]4 years ago
3 0
Albert Einstein showed in one of his papers in 1905 that Brownian motion could be explained by assuming that matter is made up of tiny particles. His paper predicted how the motion should look like and also allowed for the calculation of the mass of a single molecule. Current evidence includes: 1. Individual ions (atoms with an electric charge) can be manipulated using electric and magnetic fields. 2. Elevation maps can now be made that show bumps caused by individual atoms.
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Choose all the answers that apply.
Tresset [83]
<h3>Answer:</h3>

#a.2H2 + O2 → 2H2O

#b. 2S + 3O2 → 2SO3

#d. 2K + 2H2O → H2 + 2KOH

<h3>Explanation:</h3>
  • A balanced chemical equation is one that has equal number of atoms of each element on both sides of the equation.

In this case;

  • 2H2 + O2 → 2H2O - is balanced since it has, 4 hydrogen atoms and 2 oxygen atoms on either sides of the equation.
  • 2S + 3O2 → 2SO3, is balanced. It has 2 sulfur atoms and 6 oxygen atoms on both side of the equation.
  • 2K + 2H2O → H2 + 2KOH, is balanced , 2 potassium atoms, 4 hydrogen atoms and 2 oxygen atoms on both side of the equation.
  • On the other hand, the equations that are not balanced include;
  1. Li + Cl2 → LiCl
  2. 2Fe + Cu(NO3)2 → 2Cu + Fe(NO3)2

This is because the number of atoms of each element is not equal on both side of the equation/

5 0
3 years ago
Read 2 more answers
A substance has a mass of 61.9 g and its volume is 5.45 cm3, what is the density?
fredd [130]
Density= 11.3578 g/cm^3
7 0
3 years ago
The chemical equation shows iron(III) phosphate reacting with sodium sulfate. 2FePO4 + 3Na2SO4 Fe2(SO4)3 + 2Na3PO4 What is the t
slava [35]

<u>Answer:</u> The theoretical yield of iron(III) sulfate is 26.6 grams

<u>Explanation:</u>

To calculate the number of moles, we use the equation:

\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}     .....(1)

Given mass of iron(III) phosphate = 20.00 g

Molar mass of iron(III) phosphate = 150.82 g/mol

Putting values in equation 1, we get:

\text{Moles of iron(III) phosphate}=\frac{20g}{150.82g/mol}=0.133mol

The given chemical equation follows:

2FePO_4+3Na_2SO_4\rightarrow Fe_2(SO_4)_3+2Na_3PO_4

As, sodium sulfate is present in excess. So, it is considered as an excess reagent.

Thus, iron(III) phosphate is considered as a limiting reagent because it limits the formation of product.

By Stoichiometry of the reaction:

2 moles of iron(III) phosphate produces 1 mole of iron(III) sulfate

So, 0.133 moles of iron(III) phosphate will produce = \frac{1}{2}\times 0.133=0.0665moles of iron(III) sulfate

Now, calculating the mass of iron(III) sulfate from equation 1, we get:

Molar mass of iron(III) sulfate = 399.9 g/mol

Moles of iron(III) sulfate = 0.0665 moles

Putting values in equation 1, we get:

0.0665mol=\frac{\text{Mass of iron(III) sulfate}}{399.9g/mol}\\\\\text{Mass of iron(III) sulfate}=(0.0665mol\times 399.9g/mol)=26.6g

Hence, the theoretical yield of iron(III) sulfate is 26.6 grams

8 0
4 years ago
Does all Newton's laws work together
9966 [12]
I believe so ya.....
6 0
3 years ago
Help please!!!
Lina20 [59]

Answer:i think its 6 what do you think

Explanation:

5 0
3 years ago
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