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Deffense [45]
3 years ago
5

Chalk markings cannot be easily rubbed off from a black board if kept for a long time.why?

Chemistry
1 answer:
snow_tiger [21]3 years ago
3 0

The chalk particles embed themselves into the small pores on the surface.

Although a chalkboard seems smooth to the touch, it is quite rough at the microscopic level, with <em>pores</em> that reach below the surface.

When you drag chalk across the board, friction causes small particles of chalk to rub off onto the surface.

If you leave the markings for a long time, some of the chalk particles will work their way into the pores.

A brush will remove the surface particles, but <em>it will not be able to get at the particles in the pores</em>.

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aleksley [76]

Answer:

It will require<u> second round</u> of the cycle to release 14C0_2

Explanation:

<u>Reason behind the requirement of second round of the cycle to release </u>CO_2 -:

The C4 carbon of succinyl CoA is acetyl from acetyl CoA. Succinyl CoA is converted to succinate, which is then converted to fumarate, fumarate, malate, and eventually oxaloacetate. 14C will be found in oxaloacetate at either C1 or C4. During the second round of the loop, each of these carbons will be converted to carbon dioxide.

7 0
3 years ago
The chemical shift of the CH3 protons in diethylether is δ = 1.16 and that of the CH2 protons is 3.36. What is the difference in
grandymaker [24]

Answer:

Where Blocal = local magnetic field between the two regions of the molecule

Blocal = (1-σ)B0

ΔBlocal = (1-σ1)B0 - (1-σ2)B0 = (σ2 - σ1)B0 = ΔσB0 ≈ ΔδB0 x 10∧-6

= (3.36-1.16) x 10∧-6 x B0 = 2.20 x 10∧-6B0

(a) ΔBlocal = 2.20 x 10∧-6 x 1.9T = 4.2 μT

(b) ΔBlocal = 2.20 x 10∧-6 x 16.5T = 36.3 μT

Explanation:

5 0
3 years ago
Explain why landscapers might sift soil<br> that they use to construct gardens.
Studentka2010 [4]

Answer:

When one desires to remove debris from the garden then a soil sifter can be used as a beneficial tool. Based on the needs, it can be of different kinds. A landscaper may sift soil that they use at the time of constructing gardens due to many reasons:  

1. The soil becomes aerated, and thus, turn soft and easy to work upon.  

2. Sifting the soil makes the work of withdrawing undesired substances from the soil easy.  

3. It helps the plants to grow much better as the roots possess the tendency to penetrate more easily through the soil.  

4. The soil becomes healthy due to shifting, thus, helps in producing a beautiful and healthy landscape.  

6 0
3 years ago
Sedimentary rocks are a formed below earths surface as magma b a type of foliated igneous rock c formed by great heat d formed f
Alekssandra [29.7K]
Its either A or C hope one of them helps
5 0
4 years ago
Position vs Time
photoshop1234 [79]

Answer:

The starting position of this object is 3 m.

The object is traveling at a velocity of 3 m/s

Explanation:

the graph begins at 3, and increases by 3 at each second

<em>plz mark me brainliest</em>. :)

8 0
3 years ago
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