1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
STatiana [176]
2 years ago
15

How many electrons should be in an atom’s valence shell (with the exception of hydrogen and helium) to become stable? 2 4 6 8.

Physics
1 answer:
podryga [215]2 years ago
4 0

Answer:

8

Explanation:

octet rule: Atoms lose, gain, or share electrons in order to have a full valence shell of eight electrons. Hydrogen is an exception because it can hold a maximum of two electrons in its valence level.

You might be interested in
Chemical equations should be balanced so that they demonstrate the law of conservation of mass. Which of the following statement
faust18 [17]

Answer:

The products must contain the same numbers and types of atoms

7 0
2 years ago
An ideal spring is hung vertically from the ceiling. The spring constant is k = 125 N/m. A block of mass m = 650 g (1000 g = 1 k
Brrunno [24]

Answer:

0.102 m

Explanation:

k = spring constant of the spring = 125 N/m

m = mass of the block attached to the spring = 650 g = 0.650 kg

x = maximum extension of the spring

h = height dropped by the block = x

Using conservation of energy

Spring potential energy gained = Gravitational potential energy lost

(0.5) k x² = mgh

(0.5) k x² = mgx

(0.5) (125) x = (0.650) (9.8)

x = 0.102 m

3 0
3 years ago
Which is not true of the Intertropical Convergence Zone?A) It features heavy precipitation B) It's where the trade winds collide
olasank [31]
<h2>Answer: C) It's a high-pressure zone with sinking air</h2>

Explanation:

The intertropical convergence zone is the region of the terrestrial globe where the trade winds of the northern hemisphere converge with those of the southern hemisphere.  

It is characterized by being <u>a belt of low pressure</u> and inconsistent location around the equator constituted by ascending air currents, where large masses of warm and humid air converge from the north and south of the intertropical zone.  

The reason of its inconsistent location is due to the movements of the Earth with the seasons, having as a consequence the amount variation of heat energy from the sun in this region.

7 0
3 years ago
qual o nome da posição que o planeta tem maior velocidade? este ponto é mais próximo ou mais afastado do sol?
klio [65]

Em inglês, esse ponto é 'perihelion' ... 'periélio'. É o mais próximo que a Terra ou o planeta chega do sol.

7 0
3 years ago
A flywheel is a mechanical device used to store rotational kinetic energy for later use. Consider a flywheel in the form of a un
Kamila [148]

Answer:

<em>a) 6738.27 J</em>

<em>b) 61.908 J</em>

<em>c)  </em>\frac{4492.18}{v_{car} ^{2} }

<em></em>

Explanation:

The complete question is

A flywheel is a mechanical device used to store rotational kinetic energy for later use. Consider a flywheel in the form of a uniform solid cylinder rotating around its axis, with moment of inertia I = 1/2 mr2.

Part (a) If such a flywheel of radius r1 = 1.1 m and mass m1 = 11 kg can spin at a maximum speed of v = 35 m/s at its rim, calculate the maximum amount of energy, in joules, that this flywheel can store?

Part (b) Consider a scenario in which the flywheel described in part (a) (r1 = 1.1 m, mass m1 = 11 kg, v = 35 m/s at the rim) is spinning freely at its maximum speed, when a second flywheel of radius r2 = 2.8 m and mass m2 = 16 kg is coaxially dropped from rest onto it and sticks to it, so that they then rotate together as a single body. Calculate the energy, in joules, that is now stored in the wheel?

Part (c) Return now to the flywheel of part (a), with mass m1, radius r1, and speed v at its rim. Imagine the flywheel delivers one third of its stored kinetic energy to car, initially at rest, leaving it with a speed vcar. Enter an expression for the mass of the car, in terms of the quantities defined here.

moment of inertia is given as

I = \frac{1}{2}mr^{2}

where m is the mass of the flywheel,

and r is the radius of the flywheel

for the flywheel with radius 1.1 m

and mass 11 kg

moment of inertia will be

I =  \frac{1}{2}*11*1.1^{2} = 6.655 kg-m^2

The maximum speed of the flywheel = 35 m/s

we know that v = ωr

where v is the linear speed = 35 m/s

ω = angular speed

r = radius

therefore,

ω = v/r = 35/1.1 = 31.82 rad/s

maximum rotational energy of the flywheel will be

E = Iw^{2} = 6.655 x 31.82^{2} = <em>6738.27 J</em>

<em></em>

b) second flywheel  has

radius = 2.8 m

mass = 16 kg

moment of inertia is

I = \frac{1}{2}mr^{2} =  \frac{1}{2}*16*2.8^{2} = 62.72 kg-m^2

According to conservation of angular momentum, the total initial angular momentum of the first flywheel, must be equal to the total final angular momentum of the combination two flywheels

for the first flywheel, rotational momentum = Iw = 6.655 x 31.82 = 211.76 kg-m^2-rad/s

for their combination, the rotational momentum is

(I_{1} +I_{2} )w

where the subscripts 1 and 2 indicates the values first and second  flywheels

(I_{1} +I_{2} )w = (6.655 + 62.72)ω

where ω here is their final angular momentum together

==> 69.375ω

Equating the two rotational momenta, we have

211.76 = 69.375ω

ω = 211.76/69.375 = 3.05 rad/s

Therefore, the energy stored in the first flywheel in this situation is

E = Iw^{2} = 6.655 x 3.05^{2} = <em>61.908 J</em>

<em></em>

<em></em>

c) one third of the initial energy of the flywheel is

6738.27/3 = 2246.09 J

For the car, the kinetic energy = \frac{1}{2}mv_{car} ^{2}

where m is the mass of the car

v_{car} is the velocity of the car

Equating the energy

2246.09 =  \frac{1}{2}mv_{car} ^{2}

making m the subject of the formula

mass of the car m = \frac{4492.18}{v_{car} ^{2} }

3 0
3 years ago
Other questions:
  • If part of an electric circuit dissipates energy at 6 W when it draws a current of 3 A, what voltage is impressed across it?
    14·1 answer
  • A baby stroller is a rest on top of a hill which is 10 m high. The stroller and baby have a mass of 20 kg. What is the potential
    11·2 answers
  • Any value giving up from the best alternative is called​
    8·1 answer
  • What kind of things would Physics be able to answer? I. How does a hair dryer work? II. How does a lightning bolt form? III. How
    11·2 answers
  • A geological process Select one: A. is limited to acting on rocks B. shapes and changes the earth C. starts in the outer atmosph
    8·1 answer
  • Exposure to what type of radiant energy is sensed by human skin as warmth?
    10·2 answers
  • In lab you find that a 1-kg rock suspended above water weighs 10 N. When the rock is suspended beneath the surface of the water,
    9·1 answer
  • Memories
    11·1 answer
  • Which three steps, placed in the proper order, are required for a nuclear chain reaction?.
    14·1 answer
  • a plane flies 400 km east from city a to city b in 45.0 min and then 980 km south from city b to city c in 1.50 h. (assume the x
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!