All categories

2 years ago

An atom is chemically stable if its outer energy level (is filled with, contains no) electrons.

1 answer:

4 0

Well, according to the octet rule, an atom is chemically stable when the outer energy level is filled with 8 electrons. Similar is the case with noble gases. They contain 8 electrons in the outermost shell and thus they are stable.

You might be interested in

What is the definition of work when net force is parallel to the distance?

goldfiish [28.3K]

Work in general is given by W=F·d where F is the force vector and d is the displacement vector. The dot symbol is the dot product which is a measure of how parallel two vectors are. It can be replaced by the cosine of the angle between the two vectors and the vectors replaced by their magnitudes. If F and d are parallel then the angle is zero and the cosine is unity. So in this case work can be defined as the product of the magnitudes of the force and distance:
W=Fd

6 0

3 years ago

During a hurricane in 2008, the Westin Hotel in downtownNew Orleans suffered damage. Suppose a piece of glass dropped near the t

tangare [24]

Answer:

<u>77.8 m/s, downward</u>

Explanation:

For uniform acceleration motion, the average speed is equal to half the soum of the initial velocity, Vi, and the final velocity, Vf

Average speed = (Vf + Vi)/2

Also, by definition, the average speed is the distance divided by the time:

Average speed = distance / time

Then:

(Vf + Vi)/2 = 300m/6.62s

Other kinematic equation for uniform acceleration is:

Vf = Vi + a×t

Since the window is falling and the air resistance is ignored, a = g (gravitational acceleration ≈ 9.8m/s²)

Replacing the known values we can set a system of two equations:

From (Vf + Vi)/2 = 300m/6.62s

(Vf + Vi) = 2 × 300m/6.62s

Vf + Vi = 90.634 equation 1

From Vf = Vi + a×t

Vf - Vi = 9.8 (6.62)

Vf - Vi = 64.876 equation 2

Adding the two equations:

2Vf = 155.510

Vf = 77.8 m/s downward (velocities must be reported with their directions)

8 0

3 years ago

An astronaut has a mass of 75 kg and is floating in space 500 m from his 125,000 kg spacecraft. What will be the force of gravit

nikdorinn [45]

Answer:

1. 2.5×10¯⁹ N

2. 3.33×10¯¹¹ m/s²

Explanation:

1. Determination of the force of attraction.

Mass of astronaut (M₁) = 75 Kg

Mass of spacecraft (M₂) = 125000 Kg

Distance apart (r) = 500 m

Gravitational constant (G) = 6.67×10¯¹¹ Nm²/Kg²

Force of attraction (F) =?

The force of attraction between the astronaut and his spacecraft can be obtained as follow:

F = GM₁M₂ /r²

F = 6.67×10¯¹¹ × 75 × 125000 / 500²

F = 2.5×10¯⁹ N

Thus, the force of attraction between the astronaut and his spacecraft is 2.5×10¯⁹ N

2. Determination of the acceleration of the astronaut.

Mass of astronaut (m) = 75 Kg

Force (F) = 2.5×10¯⁹ N

Acceleration (a) of astronaut =?

The acceleration of the astronaut can be obtained as follow:

F = ma

2.5×10¯⁹ N = 75 × a

Divide both side by 75

a = 2.5×10¯⁹ / 75

a = 3.33×10¯¹¹ m/s²

Thus, the acceleration the astronaut is 3.33×10¯¹¹ m/s²

5 0

2 years ago

Select the appropriate shape for the given volume form

vredina [299]

Fist one is a cylinder
the second, i believe is a sphere
the third is a rectangular prism
and the last is the same as the first, a cylinder

3 0

2 years ago

Which occupies mrs space, 3m cubed or 100ft cubed

Slav-nsk [51]

The question is somewhat ambiguous.

-- It's hard to tell whether it's asking about '3 cubic meters'
or (3m)³ which is actually 27 cubic meters.

-- It's hard to tell whether it's asking about '100 cubic feet'
or (100 ft)³ which is actually 1 million cubic feet.

I'm going to make an assumption, and then proceed to
answer the question that I have invented.
I'm going to assume that the question is referring to
'three cubic meters' and 'one hundred cubic feet' .

OK. We'll obviously need to convert some units here.
I've decided to convert the meters into feet.

For 1 meter, I always use 3.28084 feet.

Then (1 meter)³ = 1 cubic meter = (3.28084 ft)³ = 35.31 cubic feet.

So 3 cubic meters = (3 x 35.31 cubic feet) = 105.9 cubic feet.

That's more volume than 100 cubic feet.

6 0

3 years ago