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Answer:

law of conservation of mass

Explanation:

According to the law of conservation of mass, mass is neither created nor destroyed.

This is actually the law that guides the balancing of chemical reaction equations.

On the left side we have four atoms of hydrogen and two atoms of oxygen. Exactly the same number of atoms of each element is seen on the right hand side in accordance with the law of conservation of mass.

Answer:

The correct answer is D. Swan received a formal education, while Edison did not.

Explanation:

I did the Unit Test :)

"Thomas Edison: The Master of Improvement,” is about Thomas Edison. Joseph Swan received a formal education, while Thomas Edison did not. Thus, option D is correct.

Thomas Edison was a known American inventor that invented the incandescent light bulb, the camera, phonograph, etc. He used electricity and worked very hard to invent the lightbulb. He received no formal education and believed in self-improvement.

He was a great inventor and fantastic improver that performed various experiments to invent the greatest inventions. Joseph Swan, on the other hand, was a physicist that developed the incandescent light bulb even before Edison.

He invented dry photographic plates and electric lightbulbs. He received proper formal education and sued Edison for the lightbulb patent infringement. He used carbon paper filaments, unlike Edison's metallic filaments in the bulb.

Therefore, in option D. both the scientists, Joseph Swan and Thomas Edison differed in receiving formal education.

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The number of moles of [tex]Fe^{2+}[/tex] in the [tex]2.0g[/tex] sample of [tex]FeCl_{2}[/tex] is [tex]0.0157[/tex] moles.

The following points should be noted about the number of moles:

Mass of the sample given as [tex]2.0g[/tex] and the molar mass of the sample as [tex]126.75g/mol[/tex].

Therefore, the number of moles of  [tex]Fe^{2+}[/tex]is obtained by dividing the mass by the molar mass.

Hence the number of moles is obtained as [tex]0.0175[/tex] moles.

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Answer:

How does adding a lone pair affect the position of existing atoms and lone pairs? It decreases the angles between the atoms - the atoms are moving closer because they are being repelled further away from the lone pairs then they are from the other atoms

Explanation:

hope it helps!

Answer:

fluorine

Explanation:

has the highest electronegativity?

Answer:

[tex]U_2=48.3kJ[/tex]

Explanation:

Hello!

In this case, since the fist law of thermodynamics helps us to understand how the change in internal energy is defined in terms of the head added to the system and the work done by the system:

[tex]Q+W=\Delta U[/tex]

In such a way, since 8.3 kJ of heat are absorbed by the system, 3.5 kJ are done by the system and the initial internal energy is 43.5 kJ, the final internal energy turns out:

[tex]U_2=U_1+Q-W\\\\U_2=43.5kJ+8.3kJ+3.5kJ\\\\U_2=48.3kJ[/tex]

Best regards!

Answer:

I saw B, he vented SUS

Explanation:

Iodoethane Is the answer.

Answer:

The reaction rate or rate of reaction is the speed at which a chemical reaction takes place. Reaction rate is defined as the speed at which reactants are converted into products. Reaction rates can vary dramatically.

Explanation:

PLS MAKE ME AS BRAINLIST

Answer:

b

Explanation:

google lol ur welcome

B: Oceanic crust is thinner and more likely to sink.

Answer:

Because while our lakes are Great, they're comparatively much smaller than oceans. And the gravitational pull isn't strong.

Answer:

A

Explanation:

Took at test on this and my teacher said it was right, hopefully I remembered right, also I answered ur other question like this I think lol

Answer:

Radiation

Explanation:

Sun rays shine on earth. Thats radiation.

Answer:

Below! ;)

Explanation:

The formula for finding density is:

Mass/Volume

So for example I have a cube, it has a mass of about 20 grams (not weight) and it's dimensions are about an inchxinchxinch. So basically it is a 20 gram cubic inch cube.

So to find it's density I have to divide mass(=20)/Volume(=1 inch^3). or simplified, 20 ÷ 1 = 20

So the density of my cube is 20..

Hope this helps!

Have a nice day!

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Answer:

oxygen is a reactant.

Explanation:

Combustion is the reaction with atmospheric oxygen forming carbon dioxide and water. Therefore, the essential condition is option B oxygen as a reactant.

Combustion is a type of reaction in which a molecule or compound reacts with atmospheric oxygen producing carbon dioxide and water. Combustion reaction is exothermic thus, evolves heat during reaction.

The general chemical equation for a combustion reaction can be written as:

[tex]\rm M + nO_{2} \rightarrow xH_{2}O + y CO_{2}[/tex]

Where, M be a reactant.

Combustion is an aerobic process that is only taking place in presence of oxygen. Hydrocarbon gases easily undergo combustion forming heat energy and they are used as fuels propellants.

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Answer:

mass

Explanation:

hope this helps you!!

Answer:

87.50g(1cm^3/1.1738g)=50.345 cm^3

Explanation:

volume units id in cubic centimeters

Answer:

Water vapor retains the same heat energy.

Answer:

water vapor gives up heat energy.

Explanation:

Took a quiz and got it right

Explanation:

Objects with a lower density will float while objects with a higher density will sink.

Since 0.8g/cm³ < 1.0g/cm³,

The log will float in freshwater.

Answer: I think its a virus

Explanation: Viruses spread form person to person just like any virus so if I'm correct the disease is a virus

Answer:

a. pentane = C5H12

b. Heptane = C7H16

c. Hexyne = C6H10

d. Octene = C8H16

e. Nonane = C9H20

Hope it helps.

1-pentene

Molecular Formula C5H10

Condensed Structural FormulaCH2=CH(CH2)2CH3

Melting Point (°C)–138

Boiling Point (°C)30

2- heptane is the straight-chain alkane with the chemical formula H3C(CH2)5CH3 or C7H16, and is one of the main components of gasoline (petrol).

Answer:

pH = 4.164

Explanation:

The first process is to find the initial moles for the base (B) & the acid (HA)

i.e.

[tex]= \dfrac{27 mL \times 0.0758 \ moles \ \ of \ B}{1000 \ mL}[/tex]

[tex]=0.0020466[/tex]

[tex]\simeq 2.047\times 10^{-3} \ moles \ of \ B[/tex]

[tex]= \dfrac{27 mL \times 0.0553 \ moles \ \ of \ HA}{1000 \ mL}[/tex]

[tex]=0.0014931[/tex]

[tex]\simeq 1.493\times 10^{-3} \ moles \ of \ HA[/tex]

The acid with base reaction is expressed as;

          HA              +      B         →             A⁻            +         HB⁺

to    1.493 × 10⁻³       2.047 × 10⁻³             -                         -

    -  1.493 × 10⁻³       1.493 × 10⁻³         1.493 × 10⁻³         1.493 × 10⁻³

            0                    5.54 × 10⁻⁴         1.493 × 10⁻³         1.493 × 10⁻³

From observation; both the acid & base weak

Given that:

The pKa for base = 4.594

The pKa for acid = 3.235

Recall that;

pKa = -log Ka

So; Ka = [tex]\mathbf{10^{-Ka}}[/tex]

By applying this:

For Base; Ka = [tex]10^{-4.594}[/tex] = 2.5468 × 10⁻⁵

For Acid:  Ka = [tex]10^{ -3.235}[/tex] = 5.821 × 10⁻⁴

After the reaction; we have the base with its conjugate acid & conjugate base of acid; Thus, since the conjugate acid of the base possesses a higher value of K, it is likely it would be the one to define the pH of the solution.

By analyzing the system, we have:

              HB⁺         + H₂O           ↔           B          +            H₃O⁺

     [tex]\dfrac{1.493\times 10^{-3}}{0.1 \ L}[/tex]                                 [tex]\dfrac{5.54\times 10^{-4}}{0.1 \ L}[/tex]

to   0.01493 M                                 0.00554   M

  -      x                                                   x                                x

    0.01493 - x                                 0.00554 - x                     x

Thus;

[tex]2.5468 \times 10^{-5} = \dfrac{(0.00554 -x)\times x}{(0.01493-x)}[/tex]

Using the common ion effect;

0.00554 - x   [tex]\simeq[/tex]  0.00554   &

0.01493 -  x   [tex]\simeq[/tex]   0.01493

∴

[tex]x = \dfrac{2.5468 \times 10^{-5} \times 0.01493}{0.00554}[/tex]

x =  [H₃O⁺] = 6.8635  × 10⁻⁵

∴

pH = -log(6.8635  × 10⁻⁵)

pH = 4.164

Answer:

75%

Explanation:

3/4 is 75% if you multiply by 25

Answer:

The sign is negative (-)

Explanation:

it shows that heat was give off to the surrounding

Answer:

102.807 kPa

Explanation:

There are some assumptions to be made in the answer. The air inside the balloon acts as an ideal gas at a given temperature conditions.

Using the combined ideal gas equation.

P= absolute pressure of the air inside the balloon.

V= volume of air inside the balloon (6.23 L= 6.23 * 10⁻³ m³)

n= moles of gas(air). (0.250 mol)

R= Universal gas constant ( 8.314 J / mol·K)

T= Temperature in Kelvin

T= 35 + 273.15 = 308.15 K

P= 102.807 * 10³ Pa

P= 102.807 kPa

Answer:

I'm not going to give you notes but I'm going to give you a tip for notes take what you think is the most important thing about the text and basically paraphrase it into your own words if that helps

Answer:

The correct answer is D

Explanation:

Wetlands are environments that are either submerged under water or are frequently wet. Marshes, swamps, bogs, and fens are examples of freshwater wetlands. Here small streams flow into larger streams and wetlands. The correct option is D.

Ecosystems in freshwater wetlands are impacted by transient or ongoing flooding. They are essential habitats for fauna (including migratory species), play a significant role in the regulation of water flow and water quality to entire catchments, and offer shelter for fauna during droughts.

In tropical and subtropical areas, mangrove swamps are coastal wetlands. In brackish to saline tidal waters, they are distinguished by halophytic (salt-loving) trees, shrubs, and other plants.

Thus the correct option is D.

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Answer:

1+2=2+1 is the answer for the question

Answer:D

Explanation:

Your skin makes vitamin D

Your skin prevents dehydration

And your skin maintains body temperature. So you are left with D

Answer:

The correct option is D.

works with bones to help you move

Explanation:

Skin is the outer layer of the body and it is the body's largest organ.

It protect the body from heat and other harmful substances.

It is comprises of three layers;

The Epidermis which is the outer layer.

The dermis which is a fibrous later that protect the Epidermis.

The subcutis is the subcutaneous layer that is beneath the dermis.

Function of the skin.

1. It's regulate body temperature

2. It's protect the body from heat and pathogenic entry.

3. It produces vitamin D

4. The skin allow sensations or feelings of touch, heat, and cold.

Therefore;

works with bones to help you move is wrong because it is the muscle that work with the bone.