A small piece of aluminum (atomic number 13) contains 10^15 atoms (The atomic number is the number of protons; it determines the (positive) electric charge of the nucleus and, thus, the number of electrons in a neutral atom.) If the piece of aluminum has a net positive charge of 3.0 uc what fraction of the electrons that the aluminum had when it was neutral would have had to be lost?

Answer:

The answer is D. Four covalent bounds

Answer:

Explanation:

Evolution is both a fact and a theory. Evolution is widely observable in laboratory and natural populations as they change over time. The fact that we need annual flu vaccines is one example of observable evolution. At the same time, evolutionary theory explains more than observations, as the succession on the fossil record. Hence, evolution is also the scientific theory that embodies biology, including all organisms and their characteristics. In this paper, we emphasize why evolution is the most important theory in biology. Evolution explains every biological detail, similar to how history explains many aspects of a current political situation. Only evolution explains the patterns observed in the fossil record. Examples include the succession in the fossil record; we cannot find the easily fossilized mammals before 300 million years ago; after the extinction of the dinosaurs, the fossil record indicates that mammals and birds radiated throughout the planet. Additionally, the fact that we are able to construct fairly consistent phylogenetic trees using distinct genetic markers in the genome is only explained by evolutionary theory. Finally, we show that the processes that drive evolution, both on short and long time scales, are observable facts.

The evolutionary theory is a scientific theory because its assumptions are well sustained by scientific data.

In conclusion, the evolutionary theory is a scientific theory because its assumptions are well sustained by scientific data.

Learn more in:

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Answer:

It has 3 electrons

Explanation:

Neutral atom has an overall charge of zero.

Since atomic number is 3, it has 3 protons [ positive charges ]. So, to be neutral, the atom must have 3 electrons [ negative charges ] to cancel out the positive charge.

Answer:

in 1 second 3m, in 2 seconds 6m, in 3 seconds 9m.

Explanation:

distance=speed × time

Explanation:

Distance travelled = Area under the line

= ut + ½ (v-u)t

Acceleration (a) = (v-u)/t and so (v-u) = at

Therefore,

Distance travelled (s) = ut + ½ (v-u)t = ut + ½ (at)t = ut + ½ at²

Thus,proved.

Answer:

don't know what class are you which subject is this

Answer:

because in vertical slope force of gravity is more than compared to slanted slope

Answer:

because gravity is always pulling objects down so when you climb upward gravity weighs you down, you have to use effort to move yourself in the opposite direction that gravity is pulling you that is why it is harder to climb up a slope.

Answer:

d is the right answer

it's was helpful to you

Answer:

I believe it's A

Explanation:

........

2: For a sample of data [tex]x_1,x_2,\ldots,x_N[/tex], the mean of this sample denoted by [tex]\overline x[/tex] is the sum of the data divided by the number of data points,

[tex]\overline x = \dfrac{x_1+x_2+\cdots+x_N}N = \displaystyle\frac1N\sum_{i=1}^N x_i[/tex]

As an example, consider [tex]x_1=-1[/tex], [tex]x_2=1[/tex], and [tex]x_3=3[/tex]. Then

[tex]\overline x = \dfrac{-1+1+3}3 = 1[/tex]

3: Standard deviation is a measure of how dispersed a given data sample is relative to the mean. Consult the plot: for a normal distribution, approximately 68% of it lies within 1 standard deviation of the mean, approx. 95% within 2 standard deviations, and approx. 99.7% within 3 standard deviations.

For instance, if the data is pulled from a normally distributed population with mean 0 and standard deviation 1, if you were to randomly select any data from the population, then 68% of the time it will fall in the range (-1, 1); 95% of the time it will fall within (-2, 2); 99.7% of the time it fall within (-3, 3).

To compute the standard deviation for a sample, for each [tex]x_i[/tex] in [tex]x_1,x_2,\ldots,x_N[/tex], you

• take the difference between [tex]x_i[/tex] and the mean [tex]\overline x[/tex]

• square this difference

• sum all the squared differences

• divide the sum by N - 1 (for a sample) or N (for a population)

• take the square root

Here the standard deviation is denoted [tex]\sigma^x_{N-1}[/tex], which I would read as "the sample standard deviation of the data x" - sample because of the N - 1 subscript.

Continuing with the previous example, we'd have

[tex]\sigma^x_{N-1} = \displaystyle \sqrt{\frac{\left(-1-1\right)^2+\left(1-1\right)^2+\left(3-1\right)^2}{3-1}} = \sqrt4 = 2[/tex]

4: Not much more to say here, the standard error is basically a measure of how accurate a given estimate is about the population based on the sample data. It's analogous to uncertainty in measuring length with a ruler, for instance.

In our example,

[tex]\alpha^x = \dfrac2{\sqrt3}[/tex]

5: If x, y, and z are random variables, then I suppose ρ is meant to denote a function of these random variables (so that ρ itself is just another random variable). For instance, you could have ρ = x + 3y - 2z. Then [tex]\overline\rho[/tex] is the sample mean of ρ.

I'm not entirely sure about the notation [tex]x(\overline x,\sigma^x_{N-1},\alpha^x)[/tex], but I suspect it's just referring to sample x with mean [tex]\overline x[/tex] and standard deviation [tex]\sigma^x_{N-1}[/tex] with standard error [tex]\alpha^x[/tex].

∆ρ is just the differential of ρ, essentially capturing how ρ changes with respect to small changes in x, y, and z. The expression you see here follows from the chain rule for differentiation.

The formula you see for [tex]\sigma^\rho_{N-1}[/tex] is the sample standard deviation of ρ. Think of ∆ρ as a vector with 3 components. Then [tex]\sigma^\rho_{N-1}[/tex] is the magnitude of this vector.

Similarly, [tex]\alpha^\rho[/tex] is the standard error for ρ, and corresponds to the magnitude of the vector whose components are the standard errors of x, y, and z.

In order for these statistics to make sense, each of x, y, and z must be samples of the same number of data. Say we take x as before [tex](x_1=-1,x_2=1,x_3=3)[/tex], along with [tex]y_1=0,y_2=4,y_3=-2[/tex] and [tex]z_1=-3,z_2=\frac12,z_3=10[/tex]. Suppose ρ = x + 3y - 2z. Then

• the sample means of y and z :

[tex]\overline y = \dfrac{0+4-2}3 = \dfrac23 \\\\ \overline z = \dfrac{-3+\frac12+10}3 = \dfrac52[/tex]

• the standard deviations of y and z :

[tex]\sigma^y_{N-1} = \sqrt{\dfrac{\left(0-\frac23\right)^2+\left(4-\frac23\right)^2+\left(2-\frac23\right)^2}{3-1}} = 2\sqrt{\dfrac73} \approx 3.06\\\\ \sigma^z_{N-1} = \sqrt{\dfrac{\left(-3-\frac52\right)^2+\left(\frac12-\frac52\right)^2+\left(10-\frac52\right)^2}{3-1}} = \dfrac{\sqrt{181}}2 \approx 6.73[/tex]

• the values of ρ :

[tex]\rho_1 = x_1+3y_1-2z_1 = -1+2\times0-2\times(-3) = 5 \\\\ \rho_2 = x_2+3y_2-2z_2 = 1+3\times4-2\times\dfrac12=12 \\\\ \rho_3 = x_3+3y_3-2z_3 = 3+3\times(-2)-2\times10 = -23[/tex]

• the sample mean of ρ :

[tex]\overline\rho = \dfrac{5+12-23}3 = -2[/tex]

• by the chain rule,

[tex]\Delta\rho = \Delta x+3\Delta y-2\Delta z[/tex]

so the standard deviation of ρ :

[tex]\sigma^\rho_{N-1} = \sqrt{\left(\sigma^x_{N-1}\right)^2 + \left(3\sigma^y_{N-1}\right)^2 + \left(-2\sigma^z_{N-1}\right)^2} \\\\\sigma^\rho_{N-1}= \sqrt{2^2 + 9\left(2\sqrt{\dfrac73}\right)^2 + 4\left(\dfrac{\sqrt{181}}2\right)^2} = \dfrac12\sqrt{\dfrac{703}3} \approx 7.65[/tex]

• the standard errors of y and z :

[tex]\alpha^y = \dfrac{2\sqrt{\frac73}}{\sqrt3} = \dfrac23\sqrt7 \approx 1.76 \\\\ \alpha^z = \dfrac{\frac{\sqrt{181}}2}{\sqrt3} = \dfrac12\sqrt{\dfrac{181}3} \approx 3.88[/tex]

• the standard error of ρ :

[tex]\alpha^\rho=\sqrt{\left(\alpha^x\right)^2+\left(3\alpha^y\right)^2+\left(-2\alpha^z\right)^2}\\\\\alpha^\rho=\sqrt{\left(\dfrac2{\sqrt3}\right)^2+9\left(\dfrac23\sqrt7\right)^2+4\left(\dfrac12\sqrt{\dfrac{703}3}\right)^2}=\sqrt{269}\approx16.40[/tex]

Answer:

I think it's possible to know if more universes exist like how we found out that more galaxies exist.

Answer:

5.3Km/hr

Explanation:

Velocity=Displacement/Time

D=4km;T=0.75hr

V=4/0.75=5.33..

John traveled at a speed of 5.3 km/h to get to his grandmother's house.

While velocity is the rate of change of an object's position with respect to time in a specific direction, speed is the rate of change of an object's position with respect to time overall. The speed of an item moving in a certain direction is referred to as its velocity. When there is a change in speed, direction, or both, the velocity also changes.

Given:

Time taken to travel, t = 0.75 h

Total distance travelled = 4 km

Let's imagine that John traveled to his grandmother's house in a single direction at a constant pace.

Velocity = Distance travelled in a given direction/Time

So, Velocity = 4 km/0.75 h = 5.3 ≈ 5km/h

John's speed in getting to his grandmother's residence was thus 5 km/h.

Learn more about the Velocity with the help of the given link:

https://brainly.com/question/19979064

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George Washington was an American political leader, military general, statesman and Founding Father of the United States, who serves as the first president of the United States from 1789 to 1797.

During the American Revolution, the led the colonial forces to victory over the British and became a national hero. In 1787, he was elected president of the convention that wrote the U.D. constitution. Two years later, Washington became the America's first president.

Answer:

Scintillators are materials that transform high-energy radiation like X-rays or gamma-rays into visible light or near-visible light. They're commonly utilized in medical diagnostics, high-energy physics, and geophysical exploration as detectors.

Explanation:

i hope this helps

Explanation:

A perfectly elastic collision is defined as one in which there is no loss of kinetic energy in the collision. An inelastic collision is one in which part of the kinetic energy is changed to some other form of energy in the collision.

Answer:

μ = tanθ = tan30 = 0.58

Explanation:

μ = force parallel/force perpendicular = mgsinθ/mgcosθ = tanθ

Answer:

which question is this

Explanation:

I don't understand sorry

Answer:

50µs

Explanation:

The conversion is that 1 second equals 1,000,000 micro seconds. Since we have 0.00005 seconds, we will multiply that to a million.

0.00005 * 1,000,000 = 50µs

Keep in mind that 50 only has 1 significant figure because any trailing zeroes before the decimal point do NOT count.

Best of Luck!

0.00005 seconds = 50 μs

Thank you

Answer:

2 m = E / c^2      where m is mass of electron

E = h v     where v is the frequency ( nu) of the incident photon

E = h c / y      where y is the incident wavelength (lambda)

2 m = h / (c y)

y = h / (2 m c)      wavelength required

y = 6.62 * 10E-34 / (2 * 9.1 * 10E-31 * 3 * 10E8)  m

y = 3.31 / 27.3 E-11 m

y = 1.21 E -12 m   = .0121 Angstrom units

Answer: I think it’s point cd and line cd

Explanation:

Answer:

Power is 3000 W

Explanation:

Momentum = mass × velocity

[tex]300 = 20 \times v \\ velocity = 15 \: {ms}^{ - 1} [/tex]

For power:

[tex]P = \frac{force \times distance}{time} \\ \\ P = force \times ( \frac{distance}{time} )[/tex]

but distance/time is velocity, so:

[tex]P = force \times velocity[/tex]

but force = mass × acceleration:

[tex]P = (mass \times acceleration) \times velocity \\ P = (20 \times 10) \times 15 \\ P = 3000 \: \: watts[/tex]

[ taken acceleration to be 10 m/s² ]

Answer is zero

Plz mark me brainlist

Explanation:

Outside two infinite parallel plates with opposite charge the electric field is zero, and that can be proved with Gauss's law using any possible Gaussian surface imaginable

Answer:

a) 2.28 m/s²

b) 159.86 m

Explanation:

Part A:

u = 0 m/s

v = 27 m/s

t = 11.8 seconds

a = ?

Formula:

v = u + at

=> 27 = 0 + a(11.8)

=> 27 = a(11.8)

=> a(11.8) = 27

=> a = 27/11.8

=> a = 2.28 m/s²

Part B:

s = ?

Formula:

s = (v² - u²)/2a

s = (27² - 0²) /2(2.28)

  = 729/4.56

  = 159.86 m

Answer:

arrow E represents cycling of carbon from living organisms to non-living organisms. this is because it is showing conversion of a carbon from the dead tree to fossil fuel.

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Darkspirit :)