What is the answer helpnme plz

QUE CAMBIOS SE PRODUJERON EN LOS MEDIOS EN EL SIGLO XX ?

iogann1982 [59]

Answer:

the answer is 10

Explanation:

The rule of three or is a way of solving problems of proportionality between three known values and an unknown value, establishing a relationship of proportionality between all of them. That is, what is intended with it is to find the fourth term of a proportion knowing the other three. Remember that proportionality is a constant relationship or ratio between different magnitudes.

If the relationship between the magnitudes is direct, that is, when one magnitude increases, so does the other, the direct rule of three must be applied. To solve a direct rule of three, the following formula must be followed:

a ⇒ b

c ⇒ x

So,

The direct rule of three is the rule applied in this case as follows: If the change in water level is 0.05 inches per hour, what is the change in water level after 24 hours?

change in water level=1.2 inches

To pass a decimal number to a fraction, you must:

Put the decimal number in a fraction above a 1. That is, the decimal number is the numerator, 1 the denominator.

Find an equivalent fraction. That fraction will carry in the denominator a 1, and as many zeros as decimals the number has.

Multiply the number above by that number.

Simplify the fraction.

Applied to this case would be:

Since the denominator was multiplied by 10, the decimal numerator is also multiplied by 10:

Simplifying the rational number (for this the numerator and denominator is divided by the same number, in this case by number 2), you get:

Finally, the change in the water level of the pond after 24 hours is 1.2 inches or what is the same inches

4 0

3 years ago

250 ml of seawater and we inked each molecule with pink color, then we mixed this 250 ml in the ocean. After mixing you took 250

Marysya12 [62]

Answer:

9.77 × 10⁹ molecules

Explanation:

Since the density of water is 1 g/cm³ = 1000 g/L

So, we find the mass of sea water in 250 mL = 0.250 L

We know density = mass/volume

mass = density × volume = 1000 g/L × 0.250 L = 250 g

Now we calculate the number of moles of sea water in 250 g, 250 mL of sea water.

number of moles n = mass of sea water,m/molar mass of water, M

molar mass of water, M = 18 g/moL

n = m/M = 250 g/18 g/mol = 13.89 mol

We now calculate the number of molecules present in the 250 mL of sea water.

n = N/N' where N = number of molecules, N' = avogadro's number = 6.022 × 10²³/mol

So,N =nN' = 13.89 mol × 6.022 × 10²³/mol = 8.36 × 10²⁴ molecules

Now, the volume of the ocean is 1.337 × 10¹⁸ m³ = 1.337 × 10¹⁵ L

Since the 250 mL sea water is mixed with the ocean, the number of molecules per liter is 8.36 × 10²⁴ molecules/1.337 × 10¹⁵ L = 6.25 × 10⁹ molecules/L

If we now take 250 mL out of the ocean, the number of molecules in this 250 mL will be 6.25 × 10⁹ molecules/L × 250 mL = 6.25 × 10⁹ molecules/L × 0.250 L = 9.77 × 10⁹ molecules.

So, we have 9.77 × 10⁹ molecules of pink molecules in the 250 mL after mixing in the ocean.

6 0

3 years ago

Albert Einstein discovered the mathematical relationship between _____ and _____.

bonufazy [111]

Answer:

energy and matter

Explanation:

5 0

3 years ago

When considering the relationship among standard free energy change, equilibrium constants, and standard cell potential, the equ

DedPeter [7]

Answer:

ΔG° = - RTLnK is used to find the standard cell potential given the equilibrium constant

Explanation:

for an ideal disolution:

⇒ ΔG = RT∑ni LnXi

∴ ΔG = ( μi - μi*)ni

∴ μ : chemical potential

∴ μ*: chem. potential of the pure component at T and P.

⇒ ΔG = μi - μi* = RT LnXi

for a equilibrium reaction:

⇒ ∑ νi*μi = 0

⇒ ΔGr = ΔG°+ RT Ln Kx = 0

⇒ ΔG° = - RT LnKx

4 0

4 years ago

A chemist is using a solution of HNO3 that has a pH of 3.75.

elena-s [515]

What you have to keep in mind is that
pH = - log[H+]
so 3.75 = -log[H+], we get [H+]= $10^{-3.75}$ ,
that is [H+]≈1.77827941× $10^{-4}$ (i see this result on calculator)
this is just what you want!

5 0

3 years ago

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