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3 years ago

Rounded to the nearest whole number, how many electrons are in an atom of zirconium? 40 51 91 131

Physics

2 answers:

alexdok [17]3 years ago

8 0

The correct answer is 40

Gre4nikov [31]3 years ago

4 0

Answer: The number of electrons in an atom of zirconium are 40.

Explanation:

Electrons are one of the subatomic particles present in an atom.

Electrons in an atom is judged by the atomic number of the atom.

Atomic number = Number of protons = Number of electrons

Atomic number of Zirconium = 40

Number of electrons will be equal to 40

Electronic configuration of Zirconium (Z = 40): $1s^22s^22p^63s^23p^64s^23d^{10}4p^65d^24d^2$

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AP Physics I, shouldn't be too hard.

Nana76 [90]

Answer:

The correct option is;

D. The kinetic energy decreases by 3·m₀·v₀²

Explanation:

The given parameters are;

The mass of object X = m₀

The initial velocity of object X = v₀

The mass of object Y = 2·m₀

The initial velocity of object Y = -2·v₀

By conservation of linear momentum, we have;

The total initial momentum = The total final momentum

Therefore, we have;

The total initial momentum = m₀·v₀ - 2·m₀·2·v₀ = The total final momentum

∴ The total final momentum = -3·m₀·v₀

The total mass of the two object after sticking together = 2·m₀ + m₀ = 3·m₀

Therefore, the velocity of the two objects after collision = (The total final momentum)/(Total mass) = -3·m₀·v₀/(3·m₀) = -v₀

The kinetic energy = 1/2 × Mass × (Velocity)²

Therefore, the kinetic energy after collision = 1/2 × (3·m₀) × v₀² = 3·m₀·v₀²/2

The kinetic energy before collision = 1/2 × m₀ × v₀² + 1/2 × (2·m₀) × (2·v₀)² = (1/2 + 4) × (m₀·v₀²)

∴ The kinetic energy before collision = 9·(m₀·v₀²)/2

The change in kinetic energy = The kinetic energy after collision - The kinetic energy before collision = 3·m₀·v₀²/2 - 9·(m₀·v₀²)/2 = -3·m₀·v₀²

Therefore, the kinetic energy decreases by 3·m₀·v₀².

5 0

3 years ago

A rock is thrown vertically upward with a speed of 18.0 m/s from the roof of a building that is 50.0 m above the ground. Assume

Andreyy89

Answer:

(a) 5.7 s

(b) 39 m/s

Explanation:

(a) u = 18 m/s

At the maximum height, the final velocity of ball is zero. lte teh time taken by the ball to go from 50 m height to maximum height is t.

use first equation of motion.

v = u + g t

0 = 18 - 10 x t

t = 1.8 s

Let the maximum height attained by the ball when it thrown from 50 m height is h'.

Use third equation of motion

v^2 = u^2 + 2 g h'

0 = 18^2 - 2 x 10 x h'

h' = 16.2 m

Total height from the ground H = h + h' = 50 + 16.2 = 76.2 m

Let t' be the time taken by the ball to hit the ground as it falls from maximum height.

use third equation of motion

H = ut + 1/2 x g t'^2

76.2 = 0 + 1/2 x 10 x t'^2

t' = 3.9 s

Total time taken by the ball to hit the ground = T = t + t' = 1.8 + 3.9 = 5.7 s

(b) Let v be the velocity with which the ball strikes the ground.

v^2 = u^2 + 2 g H

v^2 = 0 + 2 x 10 x 76.2

v = 39 m/s

4 0

4 years ago

The velocity of sound in air at STP (Standard Temperature and Pressure) is approximately 344 m/s. If the frequency of the sound

exis [7]

Answer:

0.066m

Explanation:

use the formula

velocity= frequency × wave length

344m/s = 5200Hz× wavelength

wavelength = 344m/s/5200Hz

wavelength = 0.066m(to 2 sig fig)

5 0

3 years ago

This nutrient can be hidden in food and has twice as many calories as other nutrients

vfiekz [6]

Protein has 4 cals carbs have 4 too. Fat however has 9.

6 0

3 years ago

Two objects, each with a charge of +0.15 C are separated by a distance of 3 meters.

Mrac [35]

Answer:

A . Are the masses repelling or attracting

answer:

So, positive energy densities ("masses") attract each other by gravitational interaction. This is the general idea.

B. What is the magnitude of the electrical force between the objects?

answer:

 The magnitude of the electrostatic force F between two point charges q1 and q2 is directly proportional to the product of the magnitudes of charges and inversely proportional to the square of the distance between them.

C. What would the magnitude of the force be if one of the charges was 1/3 the amount?

answer:

0.45

D. ) What would the force be if the distance between the charges was only 1 meter (with the original charges)?

answer;

Fmin=2.3×10^−28N

E: What would the force be if one of the charges was 1/3 the amount AND the distance was 1 meter?

answer;

Electrostatic force is directly related to the charge of each object. So if the charge of one object is doubled, then the force will become two times greater.

#CARRYONLEARNING:)

LOVEUALL

6 0

3 years ago