How many hours will it take for only 1.5625 mg to remain

Answer:

15. 2.66 moles .

16. 2.09L.

Explanation:

Molarity of a solution is simply defined as the mole of solute per unit litre of the solvent. Mathematically, it is represented as:

Molarity = mole /Volume.

With the above formula, let us answer the questions given above

15. Data obtained from the question include the following:

Volume of solution = 1.4L

Molarity = 1.9M

Mole of solute =.?

Molarity = mole /Volume

1.9 = mole / 1.4

Cross multiply

Mole = 1.9 x 1.4

Mole = 2.66 moles

Therefore, the mole of the solute present in the solution is 2.66 moles.

16. Data obtained from the question include the following:

Mole of solute = 0.46 mole

Molarity = 0.22M

Volume of solvent (water) =.?

Molarity = mole /Volume

0.22 = 0.46/Volume

Cross multiply

0.22 x Volume = 0.46

Divide both side 0.22

Volume = 0.46/0.22

Volume = 2.09L

Therefore, 2.09L of water is required.

Answer:

natural gas releases 50 to 60 percent less carbon dioxide than coal

Explanation:

Natural gas is a fossil fuel, though the global warming emissions from its combustion are much lower than those from coal or oil. Natural gas emits 50 to 60 percent less carbon dioxide (CO2) when combusted in a new, efficient natural gas power plant compared with emissions from a typical new coal plant [1].

Answer:

Option A. 6.75 (6.20/85.6)

Explanation:

The following data were obtained from the question:

Initial volume (V1) = 6.2cm³

Initial concentration (C1) = 6.75M

Final volume (V2) = 85.6cm³

Final concentration (C2) =.?

The final concentration can be obtained by using the dilution formula as show below:

C1V1 = C2V2

6.75 x 6.2 = C2 x 85.6

Divide both side by 85.6

C2 = (6.75 x 6.2) /85.6

C2 = 6.75 (6.2 / 85.6).

Answer:

The potential of energy availability at all locations where there is Sunlight

Explanation:

One advantage in owning a solar car is the potential of energy availability

The solar car source of energy is from the Sun which is readily available during the daytime where there is a clear sky. The energy from sunlight  is converted to to electrical energy by the photovoltaic cells on solar panels installed on the roof area of solar powered cars

The energy from the Sunlight is a form of renewable energy and therefore allows for better stability as well as the possibility of reuse of the energy

There are no emissions from the use of solar cars including noise, making the solar car very environmentally friendly.

Answer:

D

Explanation:

The indivisibility of an atom was proved wrong an atom can be further subdivided into protons, neutrons and electrons. However an atom is the smallest particle that takes part in chemical reactions......

hope i helped

pls mark brainliest,,,,,thanks

John Dalton was the chemist that gave the theory of atoms. His atomic model was incorrect as he said that the atoms cannot be further divided, but they are made of smaller particles. Thus, option D is correct.

Dalton's atomic model stated that all matter is composed of atoms that are made of elements with identical properties and mass. He further stated the formation of the compounds from the molecules.

In the theory, he stated that atoms cannot be divided further and are indivisible. This was proven wrong as the atoms are composed of sub-atomic particles namely, electrons, neutrons, and protons.

Therefore, the statement that atoms are indivisible in Dalton's atomic theory is incorrect.

Learn more about Dalton's theory here:

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Answer:

Energy, [tex]E=5.3\times 10^{-21}\ J[/tex]

Explanation:

It is required to find the energy of an electromagnetic wave with a frequency of [tex]8\times 10^{12}\ Hz[/tex]. The energy of a wave in terms of its frequency is given by :

[tex]E=h\nu[/tex]

[tex]\nu[/tex] = frequency of em wave

[tex]E=6.63\times 10^{-34}\times 8\times 10^{12}\\\\E=5.3\times 10^{-21}\ J[/tex]

So, the energy of an electromagnetic wave is [tex]5.3\times 10^{-21}\ J[/tex]

Answer:

D. [tex]5.3 * 10^-21 J[/tex]

Answer:

A. 1:3

Explanation:

If we look at the ions shown in the image attached to the question, we will notice that we have aluminum (Al^3+), a trivalent ion combining with the iodide ion (I^-).

Aluminum can easily give out its three outermost electrons to three atoms of iodine. If aluminum gives out its three electrons, it achieves the stable octet structure. Iodine atoms have seven electrons in their outermost shell. They only need one more electrons to complete their octet. This one electron can be gotten by the combination of three iodine atoms with one atom of aluminum. One electron each is transferred from the aluminum atom to each iodine atom to form AlI3 with a ratio of 1:3.

Lewis dot structure is a diagrammatic representation of valence electrons in an atom of a molecule.

The ratio of the cations to anions in the given compound is 1:3.

In the given figure, Aluminum has 3 electrons, which can be donated to iodine. Aluminum has atomic number 13, this means that if the element donates three electrons then it will attain a stable electronic configuration.

In the Iodine atom, each iodine needs only one electron to complete its octet. Thus, three atoms of iodine will be required to gain electrons from aluminum.

Thus, the ratio cation to the anion is 1:3.

To know more about lewis dot structure, refer to the following link:

https://brainly.com/question/4144781

Answer:

The answer is C3H8 + 5O2 → 3CO2 + 4H2O .

Answer:

[tex]\huge \boxed{\mathrm{C_3 H_8 +5O_2 \Rightarrow 3CO_2 +4 H_2 O}}[/tex]

[tex]\rule[225]{225}{2}[/tex]

Explanation:

[tex]\sf C_3 H_8 +O_2 \Rightarrow CO_2 + H_2 O[/tex]

Balancing Carbon atoms on the right side,

[tex]\sf C_3 H_8 +O_2 \Rightarrow 3CO_2 + H_2 O[/tex]

Balancing Hydrogen atoms on the right side,

[tex]\sf C_3 H_8 +O_2 \Rightarrow 3CO_2 +4 H_2 O[/tex]

Balancing Oxygen atoms on the left side,

[tex]\sf C_3 H_8 +5O_2 \Rightarrow 3CO_2 +4 H_2 O[/tex]

[tex]\rule[225]{225}{2}[/tex]

C) Test her suspicion by going to see an allergist to diagnose the allergy.

It's right

Answer:

it is Dead plants fall in swamp, Layers of dead plants pile up, Plant matter is buried by rocks and dirt, Plant matter is compressed and is exposed to heat, and Coal forms.

if iam right please make this into brainlest

Answer:

a) 7.22 × 10⁻¹⁹ J; b) 275 nm; c) 1.38× 10¹² electrons; d) 9.1 × 10⁻¹⁹ J

Explanation:

a) Minimum energy to eject photon

E = hf = 6.626× 10⁻³⁴ J·s × 1.09 × 10¹⁵ s⁻¹ = 7.22 × 10⁻¹⁹ J

b) Wavelength required

fλ = c

[tex]\lambda = \dfrac{c}{f } = \dfrac{2.998 \times 10^{8}\text{ m/s}}{1.09 \times 10^{15}\text{/s}} = 2.75 \times 10^{-7} \text{ m} = \textbf{275 nm}[/tex]

c) Electrons required

[tex]\text{No. of electrons} = 1.00 \times 10^{-6}\text{ J} \times \dfrac{\text{1 electron}}{7.22 \times 10^{-19}\text{ J}} = 1.38 \times 10^{12}\text{ electrons}[/tex]

d) Kinetic energy of electrons

a) Energy of photon

[tex]E = hf = \dfrac{\text{hc}}{\lambda} = \dfrac{6.626 \times 10^{-34} \text{ J$\cdot$ s}\times 2.998 \times 10^{8} \text{ m/s}}{122 \times 10^{-9}\text{ m}}= 1.63 \times 10^{-18} \text{ J}[/tex]

b) Maximum kinetic energy

The equation for the photoelectric effect is

hf = φ + KE, where  

φ = the work function of the metal — the minimum energy needed to eject an electron

KE = hf - φ = 1.63× 10⁻¹⁸ J - 7.22× 10⁻¹⁹ J = 9.1 × 10⁻¹⁹ J  

a. The energy of molybdenum to eject electron has been [tex]\rm \bold{7.22\;\times\;10^{-19}}\;J[/tex].

b. The wavelength of the radiation has been 275 nm.

c. The number of electrons present in [tex]\rm 1\;\mu J[/tex] energy has been [tex]\rm \bold{1.38\;\times\;10^1^2}[/tex].

d. The kinetic energy of the emitted electrons as been [tex]\rm \bold{9.1\;\times\;10^-^1^9\;J}[/tex].

The metal emits the energy when it returns from the excited state to ground state.

a. The energy (E) to eject electron has been given by:

[tex]E=h\nu[/tex]

Where, the value of constant, [tex]h=6.626\;\times\;10^{-34}\;\rm J.s[/tex]

The value of frequency has been given, [tex]\nu=\rm 1.09\;\times\;10^{15}\;s^{-1}[/tex]

Substituting the values for energy:

[tex]E=6.626\;\times\;10^{-34}\;\times\;1.09\;\times\;10^{15} \rm J\\\textit E=7.22\;\times\;10^{-19}\;J[/tex]

The energy of molybdenum to eject electron has been [tex]\rm \bold{7.22\;\times\;10^{-19}}\;J[/tex].

b. The wavelength ([tex]\lambda[/tex]) of the radiation has been given by:

[tex]\lambda=\dfrac{c}{\nu}[/tex]

Where, the speed of light, [tex]c=3\;\times\;\rm m/s[/tex]

The frequency has been given as, [tex]\nu=1.09\;\times\;10^{15}\;\rm s^-^1[/tex].

Substituting the values for wavelength:

[tex]\lambda=\dfrac{3\;\times\;10^8}{1.09\;\times\;10^{15}}\;\rm m\\ \lambda=2.75\;\times\;10^-^7\;m\\\lambda=275\;nm[/tex]

The wavelength of the radiation has been 275 nm.

c. The electrons ([tex]e^-[/tex]) burst out can be given as:

[tex]e^-=\dfrac{E}{E'}[/tex]

Where, the energy of radiations, [tex]E=1\;\times\;10^{-6}\;\rm J[/tex]

The energy of each electron has been calculated as, [tex]E'=7.22\;\times\;10^{-19}\;\rm J[/tex]

Substituting the values for number of electrons:

[tex]e^-=\dfrac{1\;\times\;10^-^6}{7.22\;\times\;10^-^1^9} \\e^-=1.38\;\times\;10^1^2[/tex]

The number of electrons present in [tex]\rm 1\;\mu J[/tex] energy has been [tex]\rm \bold{1.38\;\times\;10^1^2}[/tex].

d. The maximum kinetic energy (K.E.) of the radiation has been given as:

[tex]K.E.=\dfrac{hc}{\lambda} -E^'[/tex]

Where, the value of constant, [tex]h=6.626\;\times\;10^{-34}\;\rm J.s[/tex]

The speed of light, [tex]c=3\;\times\;\rm m/s[/tex]

The wavelength of the radiation, [tex]\lambda=122\;\times\;10^-^9\;\rm m[/tex]

Energy of each electron, [tex]E'=7.22\;\times\;10^{-19}\;\rm J[/tex]

Substituting the values, for kinetic energy:

[tex]K.E.=\dfrac{6.626\;\times\;10^{-34}\;\times\;3.0\;\times\;10^8}{122\;\times\;10^-^9}\;-\;7.22\;\times\;10^-^1^9\;\rm J \\\textit {K.E.}=9.1\;\times\;10^{-19}\;J[/tex]

The kinetic energy of the emitted electrons as been [tex]\rm \bold{9.1\;\times\;10^-^1^9\;J}[/tex].

For more information about photoelectric effect, refer to the link:

https://brainly.com/question/9260704

Answer:

If the reaction is going from left to right it would be synthesis, if going right to left it would be decomposition.

Explanation:

Na2O (s) + 2CO2 (g) + H2O (g) = 2 NaHCO3 (s)

Left Side

Na = 2

O = 6

C = 2

H = 2

Right Side

Na = 2

O = 6

C = 2

H = 2

Ok so is balanced already, though initial equation in question had an error in regards to the left hand side the ) should have been an O.

Hmm

Na2O (s) + 2CO2 (g) + H2O (g) = 2 NaHCO3 (s)

If it was going from right to left would be decomposition

But going from left to right it would be synthesis

Answer:

[tex]\large \boxed{\text{4.21 mol}}[/tex]

Explanation:

We must do the conversions :

mass of Zn ⟶ moles of Zn ⟶ moles of ZnO

We will need a chemical equation with masses and molar masses, so, let's gather all the information in one place.

Mᵣ:     65.38

              Zn + … ⟶ ZnO  + …

m/g:   275

(a) Moles of Zn

[tex]\text{Moles of Zn} = \text{275 g Zn}\times \dfrac{\text{1 mol Zn}}{\text{65.38 g Zn}} = \text{4.206 mol Zn}[/tex]

(b) Moles of ZnO

The molar ratio is 1 mol ZnO:1 mol Zn

[tex]\text{Moles of ZnO} =\text{4.206 mol Zn} \times \dfrac{\text{1 mol ZnO}}{\text{1 mol Zn}} = \text{4.21 mol ZnO}\\\\\text{The reaction produces $\large \boxed{\textbf{4.21 mol}}$ of ZnO}[/tex]

Explanation:

substitution reaction (also known as single displacement reaction or single substitution reaction) in a chemical reaction during which one functional group in chemical compound is replaced by an other functional group. a good example of a substitution reaction is halogenation .

Answer:

Output voltage = 600 V

Explanation:

Using the transformer equation which simply states that the ratio of the secondary to primary voltages in a transformer equals the ratio of the number of loops in their coils.

Number of input turns/Number of output turns = Voltage of input/voltage of output

10/50 = 120V/voltage of output

Voltage of output = 120 V/0.2

Voltage of output = 600 V

Answer:

neon - non metal

Explanation:

Answer:

Answer:

d.

Explanation:

a. beta radiation - electrons that have negative charge, and when they leave a nucleus , the charge or atomic number of the nucleus will change.

b. Alpha radiation - nuclei of He, atomic number and mass number will be changed.

c. positron radiation - positrons are similar to electrons but have positive charge, so , the charge or atomic number of the nucleus will change.

d. gamma radiation is electromagnetic waves, does not have charge and mass.

Answer:

the answer is d. gamma radiation

Explanation:

Answer:

The answer would be B the temperature of the juice was the temperature of the surrounding air...trust me lolllllllllllllllll

Answer:

Hox are transcription factors that are evolutionarily conserved across bilaterians and, therefore, they share sequence homology between paddlefish and humans .

Explanation:

The Hox genes represent a family of homeodomain transcription factors that play roles in the development of the axial and appendicular skeleton, being therefore critical during embryonic development. In this case, the human Hox genes are homologous to homeobox genes found in the paddlefish. These genes have a DNA-binding domain of 60 amino acids which is evolutionarily conserved in bilaterian species including paddlefish and human species.

The role of the salt bridge is to assure the neutrality of both compartments.

Answer: 1500 kg•m/s north

Explanation:

A PE X

Answer:

All living organisms need food for their body metabolism. Food helps in the provision of basic nutrients for the body’s survival and growth.

When the Cheetah eats the Zebra, enzymes acts on the Zebra molecules and converts it into smaller molecules.

The smaller molecules broken down are then readily absorbed and used by the cells of the Cheetah.

Answer:

d)carbon(iv)oxide/carbon(ii)oxide

e)Calcium,carbon,oxygen

f)carnonhydride

g)Carbonhydrate

h)hydrogen+oxygen

I)Iron sulphide

j)Magnesiumoxide

m)magnesium hydroxide+hydrogen gas

d)carbon dioxide

Answer:

The name of the hotel can be the Red dust hotel. And the theme could red and rocky

Explanation:

Answer:

The answer is 2C8H18 + 25O2 → 16CO2 + 18H2O .

(Correct me if I am wrong)

Answer:

Its b. Magnetic reversal

Explanation:

Answer:

B

Explanation:

i just did it

Answer:

Need more details to answer correctly.

Do you mean in general why are populations decreasing?

Well for jaguars this is due to poaching and deforestation.

For Sloths this is due to deforestation.

In an ecosystem, the jaguars and sloths  are not growing and thriving due to deforestation and poaching.

Ecosystem is defined as a system which consists of all living organisms and the physical components with which the living beings interact. The abiotic and biotic components are linked to each other through nutrient cycles and flow of energy.

Energy enters the system through the process of photosynthesis .Animals play an important role in transfer of energy as they feed on each other.As a result of this transfer of matter and energy takes place through the system .Living organisms also influence the quantity of biomass present.By decomposition of dead plants and animals by microbes nutrients are released back in to the soil.

Learn more about ecosystem,here:

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Answer:

0.000000000000005 mm

Explanation: