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3 years ago

____ Turns food into a new form: a form that cells can use. A chemical change. B grinding. C physical change. D mixing. Why

1 answer:

7 0

The correct answer is A. Chemical change turns food into a new form, a form that cells can use. It happens because the food we eat cannot be processed by cells so several reactions inside our body allow chemical changes to the food we ate turning them to usable compounds for our cells.

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What is electroluminescence? Give one example.

vredina [299]

Answer:

electroluminescence is a production of light by the flow of electrons, as within certain crystals. An example is at most resataurants with a bright sign that either says open or closed.

Explanation:

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3 years ago

How many grams nano3 add to 500g of h20 prepare solution .5 molal nano3?

Scilla [17]

Answer is: mass of sodium nitrate is 21,25 g.
m(H₂O) = 500 g · 1 kg/1000 g = 0,5 kg.
b(solution) = 0,500 m = 0,500 mol/kg.
m(NaNO₃) = ?
b(solution) = n(NaNO₃) ÷ m(H₂O).
n(NaNO₃) = 0,500 mol/kg · 0,5 kg.
n(NaNO₃) = 0,25 mol.
m(NaNO₃) = n(NaNO₃) · M(NaNO₃).
m(NaNO₃) = 0,25 mol · 85 g/mol.
m(NaNO₃) = 21,25 g.

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3 years ago

According to the equation below, how many moles of PbO are required to generate 3.88×1023 nitrogen molecules?

saul85 [17]

Answer:

1.935 mole

Explanation:

We'll begin by calculating the number of mole present in 3.88x10^23 molecules of nitrogen(N2). This can be obtained as follow:

From Avogadro's hypothesis, 1 mole of any substance contains 6.02x10^23 molecules. Therefore 1 mole of N2 contains 6.02x10^23 molecules.

Now if 1 mole of N2 contains 6.02x10^23 molecules,

Then Xmol of N2 will contain 3.88x10^23 molecules i.e

Xmol of N2 = (3.88x10^23)/6.02x10^23

Xmol of N2 = 0.645 mole

Now, we can obtain the number of moles of PbO required to generate 3.88x10^23 molecules (i.e 0.645 mole) of N2. This is illustrated below:

The equation for the reaction is given below:

3PbO + 2NH3 → 3Pb + N2 + 3H2O

From the balanced equation above, 3 moles of PbO produced 1 mole of N2.

Therefore, Xmol of PbO will produce 0.645 mole of N2 i.e

Xmol of PbO = 3 x 0.645

Xmol of PbO = 1.935 mole.

From the calculations made above,

1.935 mole of PbO will produce 3.88x10^23 molecules of nitrogen (N2).

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3 years ago

construct the lewis structure of oo . draw the structure by placing atoms on the grid and connecting them with bonds. include al

ankoles [38]

In Lewis dot structures, you draw the atom in the center and then surround the atom with its valence electrons. The Lewis structure for O is as shown in the attached diagram.

<h3>What is the Lewis structure of O ?</h3>

Lewis Structure of an atom of oxygen contains 6 electrons in the valence shell. Four valence electrons exist in lone pairs. It implies that oxygen atom must participate in two single bonds or one double bond in order to have an octet configuration.

A simplified representation of the valence shell electrons in a molecule is called Lewis Structure. It shows how electrons are arranged around individual atoms in the molecule.

To know more about Lewis structure, refer

brainly.com/question/1525249

#SPJ4

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10 months ago

Two moles of magnesium (Mg) and five moles of oxygen (O2) are placed in a reaction vessel. When magnesium is ignited, it reacts

Y_Kistochka [10]

Answer:

Explanation:

Two moles of magnesium (Mg) and five moles of oxygen (O2) are placed in a reaction vessel. When magnesium is ignited, it reacts with oxygen. What is the limiting reactant in this experiment?

Mg + O2 → MgO (unbalanced)

first, balance the equation

2Mg +O2-------> 2MgO

two magnesium atoms react with one diatomic oxygen molecule

there is a 1:1 ratio of magnesium to oxygen atoms

but we have 2 moles of magnesium atoms and 2X5 = 10 moles of oxygen atoms

the lesser magnesium LIMITS the amount of product we can make, so it is the LIMITING REAGENT.

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2 years ago