Skin color variations were caused by:

a). The change in melanin, the skin's brown pigment

b). The climate of where people migrated to

c)Diets that are rich in Vitamin D

d) All of the above

Answer:

feeding leftover or scraps to livestock

Explanation:

Because feeding leftover healthy food instead of leaving livestock to eat garbage is good for health of the animals and they give good quality of milk, eggs, meat, etc in return

Answer:

Follows are the solution to this question:

Explanation:

Please find the complete solution in the attached file.

Answer:

9

Explanation:

V=I*R

3*3

Thats the answer

Answer:

gay

Explanation:

very gay

they are impacted because people loose their home due to the wreckage that has happend and landscapes are ruined due to landslides

Answer:

Well the landscape is torn up, it goes through quite a bit of damage. the plants, animals, and water are all affected by it. when a earth quake hits it destroyes most everything, houses fall into the ground and are destroyed, people die. Earthquakes destry electrical wires and many other things

Explanation:

Sorry I did not answer it full, but you can look it up online.

Answer:

C14H30 -----> C7H14 + C2H4 +C5H10

Explanation:

Answer:

No pain, no gain is a proverb that means in order to make progress or to be successful, one must suffer. This suffering may be in a physical or mental sense. The phrase no pain, no gain was popularized in the 1980s by the American actress, Jane Fonda.

Answer:

reactants

Explanation:

please give brainlist

Answer:

Reactant

Explanation:

The order of marbles can be Aluminum, Nickel, Silver, and Rhenium.

If volume is the amount of three-dimensional space contained by a closed surface, such as the amount of space within a given cube, cylinder, or other three-dimensional shape.

Liquid volume is a way to measure an amount of liquid by describing how much three-dimensional space it occupies.

The mass of something is the amount of stuff it is made of. The volume of an object is the amount of space it usually takes up.

Density provides an easy way to calculate a body's mass from its volume or vice versa.

The mass is equal to the volume multiplied by the density (M = Vd), and the volume is equal to the mass divided by the density (V = M/d).

As per the density given, the volume of aluminum can be 1.11mL, Silver is 0.286mL, Rhenium is 0.144mL, Nickel is 0.337mL.

Thus, the order from largest to smallest will be Aluminum, Nickel, Silver, and Rhenium.

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Answer:

1.8 J/g·°C (2 sig.figs. per ΔT)

Explanation:

Given:

mass (m) = 78.9 grams

specific heat (c) = ?

Temp. Change (ΔT) = 109°C - 18°C = 91°C

Heat flow (q) = 13,240 Joules

q = m·c·ΔT => c = q/m·ΔT

∴c = 13,240J / 78.9g·91°C = 1.844 J/g·°C ≅ 1.8 J/g·°C (2 sig.figs. per ΔT)

Answer:4m/s

Explanation:The reason why that the answer is because I am Smart.

Answer: The vapor pressure of a solution in which the mole fraction of the solute is 0.200 is 80.0 torr

Explanation:

As the relative lowering of vapor pressure is directly proportional to the amount of dissolved solute.

The formula for relative lowering of vapor pressure will be,

[tex]\frac{p^o-p_s}{p^o}=i\times x_2[/tex]

where,

[tex]p^0[/tex]= vapor pressure of pure solvent = 100.0 torr

[tex]p_s[/tex] = vapor pressure of solution = ?

i = Van'T Hoff factor = 1 for nonvolatile, nonelectrolyte solute

[tex]x_2[/tex] = mole fraction of solute  = 0.200  

[tex]\frac{100.0-p_s}{100.0}=1\times 0.200[/tex]

[tex]p_s=80.0torr[/tex]

The vapor pressure of a solution in which the mole fraction of the solute is 0.200 is 80.0 torr

Answer:

d) 2

Explanation:

We are given;

n = 4, l = 1, m = -1

We can tell that is is an orbital with sub shell as 3P.

Now, from Paul's exclusion principle, each orbital will have maximum of 2 electrons of each π with a spin of +½ and -½.

Since the maximum is seen to be 2, then option D is correct.

Answer:

The limiting reagent is the reactant that is used up completely. This stops the reaction and no further products are made. ... The limiting reagent can also be derived by comparing the amount of products that can be formed from each reactant.

Answer:

The limiting reagent is the reactant that is used up completely. This stops the reaction and no further products are made. ... The limiting reagent can also be derived by comparing the amount of products that can be formed from each reactant.

Explanation:

Disclaimer not my answer I looked it up

Answer:

Boiling T° of solution = 135.6°C

Explanation:

Formula for elevation boiling point is:

ΔT = Kb . m . i

ΔT =  Boiling point of solution - Boiling point of pure solvent

Kb = Boiling point elevation constant

m = molality →  moles of solute in 1kg of solvent

i = numbers of ions dissolved

FeCl₃ →  Fe³⁺  +  3Cl⁻

In the dissociation of the ionic salt, we determined 4 moles of ions dissolved.

3 for chlorides and 1 for iron. Then i = 4

m → We convert the mass of solute to moles:

90 g . 1mol / 162.2g = 0.555 moles

650 g of solvent = 0.650 kg of solvent

m = 0.555 mol/0.650kg → 0.85

We replace data at formula

Boiling T° of solution - 129.90°C = 1.67°C . kg/mol  .  0.85 mol/kg . 4

Boiling T° of solution = 1.67°C . kg/mol  .  0.85 mol/kg . 4 + 129.90°C

Boiling T° of solution = 135.6°C

Answer:

See explanation

Explanation:

The percentage by mass of oxygen is defined as;

Mass of oxygen/ molar mass of the compound * 100/1

The average percentage by mass of oxygen = 38.933 + 38.940 + 38.871 + 38.892 + 38.900/5

The average percentage by mass of oxygen = 38.907

Percentage Error  = (|accepted value – experimental value| \ accepted value) x 100%

Percentage Error  = 39.13 - 38.907 / 39.13 * 100

Percentage Error  = 0.57%

Answer:

1700 mL / 84 mLs

Explanation:

Given that:

Volume of blood pumped per minute = 84 /mLs

Time it takes to circulate 1700 mL of blood :

Time taken = Volume of blood circulate / Rate

Hence, to circulate 1700 mL of blood :

Time taken = 1700 mL / 84 mLs

Answer:

a

Explanation:

sugar is composed of different elements combined in a manner form

Answer:

0.03 M

Explanation:

The computation of the molarity of the diluted HCI is given below:

As we know that

(M1) × (V1) = (M2) × (V2)

Now

(M2) = {(M1) × (V1)} ÷ (V2)

or

Molarity of the diluted HCl,(M2) is

= {6 × 25} ÷ 5000

= 0.03 M

Explanation:

1 mole = 6.02 x 10^23 atoms (Avogadro’s number)

Step 1) Determine how many grams of a substance are in the problem

Step 2) Find the amount of grams in 1 mole of the substance

3) Multiply step one by step two

Answer:

Ionic Substance is....

Explanation:

In chemistry, an ionic compound is a chemical compound composed of ions held together by electrostatic forces termed ionic bonding. The compound is neutral overall, but consists of positively charged ions called cations and negatively charged ions called anions.

Answer:

[tex]$MnO^-_4$[/tex]  is a strong oxidizing agent.

Explanation:

The 5d orbitals of Re are higher in energy than 3 d orbitals of Mn. So an LMCT ligand to metal charge transfer excitation requires more energy of [tex]$ReO^-_4$[/tex].

Also, since the molecular orbitals are derived primarily from  3d orbitals of [tex]$MnO^-_4$[/tex] are lower in energy than the corresponding MO's of   [tex]$ReO^-_4$[/tex], [tex]$MnO^-_4$[/tex]  is better able to accept the electrons.

So it is a better oxidizing agent.

The ligand to metal charge transfer band in ReO4- occurs in the near UV region hence ReO4 - appears colorless.

The electron configuration of Re is Xe 4f14 5d5 6s2 and the electron configuration of Mn is [Ar] 3d5 4s2. We can see that Mn^7+ and Re^7+ have empty d orbitals.

The color of MnO4 - must result from ligand to metal charge transfer hence the purple color of MnO4 -. In the case of ReO4 -, the ligand to metal charge transfer occurs at a much higher energy owing to the fact that 5d orbitals are involved. This transition occurs in the near UV region hence ReO4 - appears colorless. The ligand to metal charge transfer in MnO4- involves lower energy 3d orbitals hence it occurs in the visible region of the spectrum.

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Answer: the baseball bat transfor its energy in the ball.

Explanation: you hit it with one and find out and tell me what you think what happen.

Answer:

Distance = 200 km

Distance = 204 km

Speed = 77 km/h

Time = 21.42 h

Explanation:

Given:

A.

Speed = 100 km/h , Time = 2 h

Find:

Distance

B.

Speed = 68 km/h , Time = 3 h

Find:

Distance

C.

Distance = 154 km , Time = 2 h

Find:

Speed

D.

Distance = 1500 km speed = 70 km/h

Find:

Time

Computation:

Speed = distance / time

A.

Distance = 100 x 2

Distance = 200 km

B.

Distance = 68 x 3

Distance = 204 km

C.

Speed = 154 / 2

Speed = 77 km/h

D.

Time = 1500 / 70

Time = 21.42 h

Answer:

[Kr] 4d10 5s2 5p4

Explanation:

The Symbol I represents Iodine. It has atomic number of 53. The full electronic configuration is given as;

1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p5

However the question requested for the configuration of I+.

I+ is a cation and it simply refers to an iodine atom that has lost a single electron. The electronic configuration of I+ is given as;

1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p4

Using Noble gas shorthand representation, we have;

[Kr] 4d10 5s2 5p4

Answer:

A)3410K

B)5678.6 °F

Explanation:

✓ To convert Celcius to Kelvin expression below can be used

K= °C + 273

We were given T=3137 °C

= 3137 + 273= 3410K

✓To convert Celcius to Fahrenheit, expression below can be used

°F =(°C × 9/5) + 32

We were given T=3137 °C

°F= (3137 × 9/5) + 32

= 5646.6+32

=5678.6 °F

Answer:

Rate = k[NH₄OH]²

k = 6.17

Explanation:

We have concentrations of NH₄OH along with the given times. To determine the rate law of the reaction we need to determine first the order of reaction. This reaction can be order zero, first or second order. The expressions for each are the following:

Zero order:

k = [A₀] - [A] / t

First order:

k = 1/t * ln([A₀]/[A])

Second order:

k = (1/t) * (1/[A₀] - 1/[A])

And from here, the next part is easier. We just need to determine hat order is, calculating the value of k at two different times. If the value of k is constant, then we can say that the reaction is of that order.

Let's suppose its order zero (t = 1 and t = 2, [A₀] = 0.200 M):

k1 = 0.2 - 0.0895 / 1 = 0.1105

k2 = 0.2 - 0.577 / 2 = -0.1885

From this results we can conclude it's not zero order.

Let's suppose its order 1:

k1 = ln(0.2/0.0895) / 1 = 0.8041

k2 = ln(0.2/0.577) / 2 = 0.1733

It's not first order either, so we can conclude that this reaction is of 2nd order and the rate law would be:

Now that we know it's a second order reaction, we can determine the value of k using its expression:

k = (1/t) (1/[A] - 1/[A₀])

k = ln(1/0.0895 - 1/0.2) (1/1)

k = 6.17

And to confirm this value, let's calculate k for t = 2 s

k = (1/2) (1/0.0577 - 1/0.2)

The value is constant, so this is the true value of k.

Hope this helps

Answer:

Frogs

Explanation:

Answer:

Hello there! I'm assuming frog and or dog :)

Answer: The empirical formula is [tex]C_{17}H_{19}O_3N[/tex]

Explanation:

Mass of C= 17.900 g

Mass of H = 1.680 g

Mass of O = 4.225 g

Mass of N = 1.228 g

Step 1 : convert given masses into moles.

Moles of C =[tex]\frac{\text{ given mass of C}}{\text{ molar mass of C}}= \frac{17.990g}{12g/mole}=1.5moles[/tex]

Moles of H =[tex]\frac{\text{ given mass of H}}{\text{ molar mass of H}}= \frac{1.680g}{1g/mole}=1.680moles[/tex]

Moles of O =[tex]\frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{4.225g}{16g/mole}=0.264moles[/tex]

Moles of N =[tex]\frac{\text{ given mass of N}}{\text{ molar mass of N}}= \frac{1.228g}{14g/mole}=0.087moles[/tex]

Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.

For C = [tex]\frac{1.5}{0.087}=17[/tex]

For H = [tex]\frac{1.680}{0.087}=19[/tex]

For O =[tex]\frac{0.264}{0.087}=3[/tex]

For N = [tex]\frac{0.087}{0.087}=1[/tex]

The ratio of C : H: O: N = 17: 19: 3: 1

Hence the empirical formula is [tex]C_{17}H_{19}O_3N[/tex]