how many atoms of hydrogen are in 420g sample of water

Natural selection cannot work if beneficial traits are not hereditary

Answer:

favors organisms well adapted to the environment

cannot work if beneficial traits are not hereditary

is often called survival of the fittest

Explanation:

NOT

is random

happens by chance

The molar mass of the gas : 18 x 10⁻³ kg/mol

Given

An unknown gas has one third the root mean square speed of H2 at 300 K

Required

the molar mass of the gas

Solution

Average velocities of gases can be expressed as root-mean-square (V rms)  

[tex]\large {\boxed {\bold {v_ {rms} = \sqrt {\dfrac {3RT} {Mm}}}}[/tex]

T = temperature, Mm = molar mass of the gas particles  , kg/mol

R = gas constant 8,314 J / mol K  

v rms An unknown gas = 1/3 v rms H₂

v rms H₂ :

[tex]\tt v_{rms}=\sqrt{\dfrac{3\times 8.314\times 300}{2.10^{-3}} }\\\\v_{rms}=1934.22[/tex]

V rms of unknown gas =

[tex]\tt \dfrac{1}{3}\times 1934.22=644.74[/tex]

[tex]\tt 644.74^2=\dfrac{3\times 8.314\times 300}{M_{gas}}\\\\M_{gas}=18\times 10^{-3}~kg/mol[/tex]

The percent yield : 73.5%

Given

Reaction

C+2H₂⇒CH₄

Required

The percent yield

Solution

mol of Carbon(as a limiting reactant) :

[tex]\tt \dfrac{100}{12}=8.3[/tex]

mol CH₄ based on C, and from equation mol ratio C : CH₄, so mol CH₄ = 8.3

Mass of Methane(theoretical yield) :

[tex]\tt mass=mol\times MW\\\\mass=8.3\times 16=133.3~g[/tex]

[tex]\tt \%~yield=\dfrac{actual}{theoretical}\times 100\%\\\\\%yield=\dfrac{98}{133.3}\times 100\%=73.5\%[/tex]

Answer:

That's because the glass walls of the greenhouse trap the Sun's heat. The greenhouse effect works much the same way on Earth.

Explanation:

Gases in the atmosphere, such as carbon dioxide, trap heat just like the glass roof of a greenhouse. These heat-trapping gases are called greenhouse gases.

Answer:

Shear

Tension

Compression

Explanation:

The 3 stress forces are;

-shear

-tension

-compression

1) Shear is the stress force that pushes back a mass of rock in two opposite directions which in turn will produce strike - slip faults.

2) Tension is the stress force that pulls on the crust thereby stretching in a manner that it becomes thinner at its middle which in turn will produce normal faults.

3) Compression is the stress force that makes rocks squeeze until they fold or break and this will in turn produce reverse faults.

Answer:

5

Explanation:

Answer:

2 in the first and 4 in the second

Explanation:

in an atom the first energy level has only 2 spaces for electrons, as the number electrons goes up so does the amount of energy levels

Answer:

V = 20.1 L

Explanation:

Given data:

Volume of flask = ?

Number of moles of nitrogen gas = 0.730 mol

Pressure = 698 mmHg (698/760 = 0.92 atm)

Temperature = 35.4°C

Solution:

The given problem will be solve by using general gas equation,

PV = nRT

P= Pressure

V = volume

n = number of moles

R = general gas constant = 0.0821 atm.L/ mol.K  

T = temperature in kelvin

Now we will convert the temperature.

35.4+273 = 308.4 K

by putting values,

0.92 atm× V = 0.730 mol ×0.0821 atm.L/ mol.K × 308.4 K

V = 18.48 atm.L / 0.92 atm

V = 20.1 L

Answer:

true

Explanation: all matter down to the molecular or even atomic level has a constant vibration and movement. The only time that any matter could stop moving would be at absolute zero.

Answer:

See note in Explanation

Explanation:

The modern periodic table of the elements is arranged in order of increasing atomic numbers which is also in terms of the number of protons in the nucleus. That is, for any element listed on the periodic table its atomic number equals the number of protons in the nucleus. Thus, the element with 2 protons in its nucleus would be element #2 (Helium), element #3 (Lithium) has 3 protons in its nucleus and element #4 (Beryllium) has an atomic number 4 and contains 4 protons in its nucleus.

Also, this arrangement of elements finds that elements below elements 2, 3 & 4, Neon #10; sodium #11 & magnesium #12 have similar chemical and physical properties as does elements #2, #3 & #4. Such gives rise to the 'Periodic Law' => the chemical and physical properties of the elements is a periodic function of their atomic number (or, number of protons in the nucleus).

Answer:

c warm water

Explanation:

Kinetic energy is related to temperature. The molecules in a glass of warm water have more kinetic energy (they move faster – see Racing Molecules) than the molecules in a glass of cold water. The temperature of a substance is the average* amount of kinetic energy its molecules have.

Answer:

hot water

Explanation:

Answer:

See explanation

Explanation:

Dalton's atomic theory furnished us with a basis to discuss the theory of atoms. However, not all his ideas holds up under the scruitiny of morden science.

He postulated that atoms were 'indivisible' the discovery of subatomic particles indeed show that there are smaller particles than atoms.

His postulation that atoms can neither be created nor destroyed does not hold water today because atoms are being created in nuclear reactors.

He said that atoms of all elements are exactly alike. Today we know there are isotopes of elements which are not exactly alike.

We can see that the Dalton's atomic theory did not take cognisance of the important role of subatomic particles in studying the structure of the atom. Modern atomic theory tries to look at the importance of these particles in the understanding the structure of the atom.

check out this article i found it very helpful,

I couldn't find the answer to your question.

Answer:

3.06 m

Explanation:

Time of fall be t .

h = ut + 1/2 g t² , h is height , u is initial vertical velocity = 0

h = 1/2 g t²

32 = .5 x 9.8 x t²

t = 2.55 s

During this period , diver will move in horizontal direction also .

Horizontal displacement during fall

=  horizontal velocity x time

= 1.2 x 2.55

= 3.06 m  

Answer:

Each isotope of oxygen contains 8 protons, but differs in the number of neutrons. An isotope number is a shorthand representation of its mass. Because protons and neutrons are roughly equal in mass, an isotope's number is equal to the sum of its protons and neutrons.

Explanation:

Isotopes are atoms of the same element that have different numbers of neutrons but the same number of protons and electrons. The difference in the number of neutrons between the various isotopes of an element means that the various isotopes have different masses.

Answer:

is there a picture.....????

Answer:

Solvent

Explanation:

When one substance dissolves into another, a solution is formed. A solution is a homogeneous mixture consisting of a solute dissolved into a solvent

Answer:

Dr. Moore can explain that it is continental drift.

Explanation:

continental drift is the phenomenon due to which all the continents are moving towards each other, due to this continental drift stundents afraidthat some day these continents will collide leading to catastrophe.

But this is not gonna happen in a snap, this needs a lot of time, this will take hundreds of years and even more. So there is nothing to be afraid of till then humans will find some or the other way to manage this. Plus as I said this process is very slow so there are very less chances that this could lead us to any kind of chaos or anhilation.

(Btw, this isn't my work, it's just that someone already answered this same question, and they didn't answer yours so I thought I'd give it to you.)

Answer:

1 oxygen from the lungs

Explanation:

maybe too help you breath better

Explanation:

kind of ion formed (anion or cation) and the size of the ionic charge. ... O-‐2 oxide. S-‐2 sulfide. N-‐3 nitride. P-‐3 phosphide. Table 3.1. Common, simple anions. It is critically important that you distinguish between ...

Ions and Ionic Compounds – Introductory Chemistry – 1st Canadian Edition - BC Open Textbooks

opentextbc.ca › chapter › ions-and-ionic-...

The formula Na 2Cl 2 also has balanced charges, but the convention is to use the lowest ratio of ions, which ... For the ionic compound between magnesium cations (Mg 2+) and oxide anions (O 2−), again we need only ...

[PDF] Tutorial 2 FORMULAS, PERCENTAGE COMPOSITION, AND THE MOLE FORMULAS: A chemical formula shows the elemental composition of a sub

www.eiu.edu › eiuchem › forms › t...

Ba2+ barium. HSO3. – hydrogen sulfite. MnO4. – permanganate. Al3+ aluminum. SO4. 2– sulfate. NO2. – nitrite. Sn2+ tin(II). HSO4. – hydrogen sulfate. NO3. – nitrate. Sn4+ tin(IV). S2O3. 2– thiosulfate. OH– hydroxide.

Symbols and Charges for Monoatomic Ions

www.edu.xunta.es › portal › Nomenclature

Cs+ cesium ion O2- oxide. Be2+ beryllium ion S2- sulfide. Mg2+ magnesium ion Se2- ... one K+ and one Cl¯ are required. The resulting formula is KCl. Example 3: Write the formula from the following name: barium

Barium chloride salts has a 3 to 2 ratio of cations to anions. thus option C is correct.

Barium Chloride an inorganic salt which is composed up of barium cations (Ba2+) and chloride anions (Cl–), otherwise named as  Barium Muriate or Barium dichloride.

It is a white solid , water-soluble, hygroscopic and gives a slight yellow-green color to a flame,  extensively used in the industry mainly The sulfate is used in white paints where as Barium chloride is poisonous in nature.

It is soluble in water which dissociate into barium cations and chloride anions in its dissolved state, However, the solubility of this compound in water is temperature-dependent.

For more details barium chloride,  visit

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Answer:

113 kJ or 113,000J

Explanation:

Since we are condensing it, a physical change in the state of matter is occurring. 113 kJ or 113,000J because of the following equation: Q = 2260 times 50.  2260 is the Heat of Vaporization constant.

Answer:

OB- one or more cells

Explanation:

hope this helps :)

The correct answer is C. ΔHθf

We define the standard enthalpy of formation as the enthalpy change when one mole of a substance is formed from its elements under standard conditions. The standard conditions are 1 atm pressure, 273 K temperature and 1 M concentration.

The standard enthalpy of formation is denoted using the symbol ΔHθf.

Hence, ΔHθf is the enthalpy change when 1 mole of a substance is formed from its elements under standard conditions.

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The geologic process that directly forms beaches on the shores of the bay should be considered as the sediment deposition.

The Deposition refer to the laying down of sediment that should be carried by wind, where the water should be flowing down or there is the sea or ice. Sediment could be transported just like the pebbles, sand ,and mud, or as salts mix in the water.

Therefore, The geologic process that directly forms beaches on the shores of the bay should be considered as the sediment deposition.

Learn more about geologic here: https://brainly.com/question/3101097

Answer:

Elephant Toothpaste

Extra

Make Elephant Toothpaste

Pour 1/2 cup hydrogen peroxide solution, 1/4 cup dishwashing soap, and a few drops of food coloring into the bottle. Swish the bottle around to mix the ingredients. Set the bottle in a sink or outdoors or some other place where you won't mind getting wet foam everywhere.

In a separate container, mix a packet of active yeast with a little warm water. Give the yeast about five minutes to activate before proceeding to the next step.

When you are ready to do the demo, pour the yeast mixture into the bottle. The reaction occurs immediately upon the addition of the yeast.

I don't know if this will help but here you go.

Answer:

Plants can split starch into it's simpler glucose units for use as energy when needed. Cellulose is known as a structural carbohydrate because of the fibers formed by it's molecules. It is the major component of plant cell walls and comprises over half of the carbon found on planets.

Explanation:

I majored in Chemistry

Answer:

A option

Explanation:

Because recatants are in solid form having less enetropy and products are liquid form having more entropy

While other options reactants and products are in same phase gas phase having same entropy

The reaction that would result in increased entropy is the combustion reaction;

KNO3(s)--->K+(aq)+NO3-(aq). Option A

This is further explained below

Generally, a combustion reaction is simply a combustion process that occurs when a material combines with oxygen gas, producing energy as light and heat.

In conclusion, the chemical reaction KNO3(s)--->K+(aq)+NO3-(aq) is has all properties of a combustion reaction as the solid reactants gives an aq solution.

Read more about Chemical reaction

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Actual yield : 45.752 g ⇒no option

Given

The theoretical yields of Cl₂ : 65.35 g and 68.08 g

Required

The actual yield

Solution

Reaction

4 HCl (aq) + MnO₂ (s) → MnCl₂ (aq) + Cl₂ (g) + 2H₂O (l)

Because there are two theoretical yields, then we can choose the smallest one because the value is usually determined from the limiting reactant (in this reaction the limiting reactant is MnO₂)

So 65.36 g is The theoretical yields of Cl₂

Then the actual yield :

[tex]\tt \%yield=\dfrac{actual}{theoretical}\times 100\%\\\\actual=\%yield\times theoretical\\\\actual=70\%\times 65.36=45.752[/tex]

Explanation:

mass H2O2 = 55 mL(1.407 g/mL) = 80.85 g

molar mass H2O2 = 2(1.01 g/mol) + 2(16.00 g/mol) = 34.02 g/mol

moles H2O2 = 80.85 g/34.02 g/mol = 2.377 moles H2O2

For each mole of H2O2 you obtain 0.5 mole of O2 (see the equation).

moles O2 = 2.377 moles H2O2 (1 mole O2)/(2 moles H2O2) = 1.188 moles O2

Now, you need the temperature.  If you are at STP (273 K, and 1.00 atm) then 1 mole of an ideal gas at STP has a volume of 22.4 L.  Without temperature you are not really able to continue.  I will assume you are at STP.

Volume O2 = 1.188 moles O2(22.4 L/mole) = 0.0530 L of O2.

which is  53 mL.

Answer:

The number of drops depends upon the size of the drops. So, basically, 1 ml has a drops of 20

so 2000 mo will have a 40k drops