Please help and thank you

How many electrons are in the third energy level? 2 8 18 20

Blababa [14]

Answer:

B)8

Explanation:

In the first energy level you can have, at most, 2. Every energy level after that wants to have 8 electrons. Valence electrons I believe.

Hope this helps, have a nice day! (^-^)

6 0

3 years ago

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In this diagram, medium A represents water and medium B represents air. The phenomenon in this diagram, moving from A to B, is c

Readme [11.4K]

Its C) refraction
hope its may help you

6 0

3 years ago

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How does the interstellar medium affect our view of most of the galaxy?

Vsevolod [243]

Answer: It prevents us from seeing most of the galactic disk with visible and ultraviolet light.

(hope this helps) :)

8 0

2 years ago

Andrea and Chuck are riding on a merry-go-round. Andrea rides on a horse at the outer rim of the circular platform, twice as far

marta [7]

a) Their angular speeds are the same

b) Andrea's tangential speed is twice the value of Chuck's tangential speed

Explanation:

a)

The angular speed of Andrea and Chuck is the same.

Let's call $\omega$ the angular speed at which the merry-go-round is rotating. We know that the angular speed is defined as:

$\omega= \frac{2\pi}{T}$

where

$2 \pi$ is the angular displacement covered in one revolution

T is the period of revolution

The merry go round is a rigid body, so all its point cover the same angular displacement in the same time: this means that it doesn't matter where Andrea and Chuck are located along the merry-go-round, their angular speed will still be the same.

b)

For an object in circular motion, the tangential speed is given by

$v=\omega r$

where

$\omega$ is the angular speed

r is the distance from the centre of rotation

Here let's call $r_c$ the distance at which Chuck is rotating, so his tangential speed is

$v_c = \omega r_c$

Now we know that Andrea is rotating twice as far from the centre, so at a distance of

$r_a = 2 r_c$

So his tangential speed is

$v_a = \omega r_a = \omega (2 r_c) = 2(\omega r_c) = 2 v_c$

So, Andrea's tangential speed is twice the value of Chuck's tangential speed.

Learn more about circular motion:

brainly.com/question/2562955

brainly.com/question/6372960

#LearnwithBrainly

5 0

3 years ago

Determine the amount of work done by the engine of a car with a mass of 2500 kg when it accelerates from 45 mph to 65 mph. (Use

Y_Kistochka [10]

Answer:

amount of work done, W = 549.36 kJ

Given:

mass of a car engine, m = 2500 kg

initial velocity, u = 45 mph

final velocity, v = 65 mph

1 mile = 1609

Solution:

We know that 1 hour = 3600 s

Now, velocities in m/s are given as:

u = 45 mph = $\frac{45\times 1609}{3600}$ = 20.11 m/s

v = 65 mph = $\frac{65\times 1609}{3600}$ = 29.05 m/s

Now, the amount of work done, W is given by the change in kinetic energy of the car and is given by:

W = $\frac{1}{2}m\Delta v^{2}$

W = $\frac{1}{2}m\times (v^{2} - u^{2})$

W = $\frac{1}{2}2500\times (29.05^{2} - 20.11^{2})$

W = 549.36 kJ

3 0

3 years ago