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3 years ago

What evidence did Alfred Wagner have to support his idea of continental drift

1 answer:

8 0

Alfred Wagner's evidence began at the simplest form that the continents appeared to<em> fit</em> together like pieces to a puzzle. It wasn't only that though. The evidence showed that the same rocks and fossils existed on separate continents - the same continents that if pieced together would be connected.

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Model B: In this model the atom is a solid sphere that cannot be divided up into smaller

vivado [14]

Answer:

They are called corpuscles

Explanation:

5 0

3 years ago

How many liters of hydrogen gas will be produced at STP from the reaction of 7.179×10^23 atoms of magnesium with 54.219g of phos

Alexeev081 [22]

Answer: The volume of hydrogen gas produced will be, 12.4 L

Explanation : Given,

Mass of $H_3PO_4$ = 54.219 g

Number of atoms of $Mg$ = $7.179\times 10^{23}$

Molar mass of $H_3PO_4$ = 98 g/mol

First we have to calculate the moles of $H_3PO_4$ and $Mg$ .

$\text{Moles of }H_3PO_4=\frac{\text{Given mass }H_3PO_4}{\text{Molar mass }H_3PO_4}$

$\text{Moles of }H_3PO_4=\frac{54.219g}{98g/mol}=0.553mol$

and,

$\text{Moles of }Mg=\frac{7.179\times 10^{23}}{6.022\times 10^{23}}=1.19mol$

Now we have to calculate the limiting and excess reagent.

The balanced chemical equation is:

$3Mg+2H_3PO_4\rightarrow Mg(PO_4)_2+3H_2$

From the balanced reaction we conclude that

As, 3 mole of $Mg$ react with 2 mole of $H_3PO_4$

So, 0.553 moles of $Mg$ react with $\frac{2}{3}\times 0.553=0.369$ moles of $H_3PO_4$

From this we conclude that, $H_3PO_4$ is an excess reagent because the given moles are greater than the required moles and $Mg$ is a limiting reagent and it limits the formation of product.

Now we have to calculate the moles of $H_2$

From the reaction, we conclude that

As, 3 mole of $Mg$ react to give 3 mole of $H_2$

So, 0.553 mole of $Mg$ react to give 0.553 mole of $H_2$

Now we have to calculate the volume of $H_2$ gas at STP.

As we know that, 1 mole of substance occupies 22.4 L volume of gas.

As, 1 mole of hydrogen gas occupies 22.4 L volume of hydrogen gas

So, 0.553 mole of hydrogen gas occupies $0.553\times 22.4=12.4L$ volume of hydrogen gas

Therefore, the volume of hydrogen gas produced will be, 12.4 L

4 0

3 years ago

The cost, C C, of producing x x Totally Cool Coolers is modeled by the equation C = 0.005 x 2 − 0.25 x + 12 C=0.005x2-0.25x+12 H

neonofarm [45]

Answer:

25 coolers are need to be produce and sell in order to minimize the cost.

Explanation:

$C = 0.005x^2-0.25x+12$ ..[1]

Differentiating the given expression with respect to dx.

$\frac{dC}{dx}=\frac{d(0.005x^2-0.25x+12)}{dx}$

$\frac{dC}{dx}=0.01x-0.25+0$

Putting , $\frac{dC}{dx}=0$

$0=0.01x-0.25+0$

$0.01x=0.25$

x = 25

Taking second derivative of expression [1]

$\frac{d^2C}{dx^2}=\frac{d(0.01x-0.25)}{dx}=0.01$

$\frac{d^2C}{dx^2}>0$ (minima)

25 coolers are need to be produce and sell in order to minimize the cost.

3 0

3 years ago

What happens after sound waves create vibrations in the ear?

otez555 [7]

Explanation:

3 little bones in ear takes that vibration and empowers them. Then they transfer the vibrations to next part of ear.

7 0

3 years ago

Choose all the answers that apply.

Andru [333]

Answer:

I think this the right answer maybe, the space between neurons is called a synapse. The nucleus of a neuron is located in the cell body. Axons carry messages toward the cell body. These are the true ones I think.

Explanation:

3 0

3 years ago