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3 years ago

Why does helium have more spectral lines than hydrogen?

1 answer:

8 0

<span>This is because Helium has two valence electrons compared to Hydrogen which has only one. Helium has more energy levels for an electron to jump thus more spectral lines to occur. The spectral lines relating to each change of energy level would be more grouped together and hence the greater chance of them falling in the visible range.</span>

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How would the model change as the atom forms bonds? The third shell would have eight electrons after the atom gains seven electr

atroni [7]

Answer:

The third shell would be empty, so the eight electrons on the second level would be the outermost after the atom lost one electron

Explanation:

When an atom is bonded with other atoms, a more stable configuration must be reached, which is why the energy of the molecule is less than the energy of the individual atoms, for this to happen in general, electrons are shared or lost and gained in each atom, depending on the electronegative of the same.

If we analyze an atom within the molecule, its last shell is full, in the case of atoms with few electrons in this shell, they are lost and in the case of many electors in this shell, it gains electrons to have eight (8) in total.

When reviewing the different answers, the correct one is:

* The third shell would be empty, so the eight electrons on the second level would be the outermost after the atom lost one electron

4 0

3 years ago

Read 2 more answers

Starting from rest, a car takes 2.4s to travel 15m. Assuming a constant acceleration, how long will it take the car to travel th

Alborosie

Answer:

T = 2.4 + 2.4 = 4.8 [s]

Explanation:

In order to solve this problem, we must use the following kinematics equation and calculate the acceleration value.

$x=x_{o} +v_{o}*t+(\frac{1}{2})*a*t^{2}$

Vo = inital velocity = 0

x - xo = 15 [m]

t = time = 2.4 [s]

15 = 0.5*a*(2.4)^2

a = 5.208 [m/s^2]

We can use the same equation to find the time.

30 = 15 + 0.5*(5.208)*t^2

t = 2.4 [s]

T = 2.4 + 2.4 = 4.8 [s]

7 0

3 years ago

A 22.0 kg child slides down a slide that makes a 37.0° angle with the horizontal. (a) What is the magnitude of the normal force

patriot [66]

Answer:

(a) 172.185 N

(b) $53^{\circ}$

Solution:

As per the question:

Mass of the child, m = 22.0 kg

Angle, $\theta = 37.0^{\circ}$

Now,

(a) The magnitude of the normal force exerted by the slide on the child:

$F_{N} = mgcos\theta$

$F_{N} = 22\times 9.8cos37^{\circ} = 172.185\ N$

Now,

(b) The angle from the horizontal at which the force is directed is:

$90^{\circ} - 37^{\circ} = 53^{\circ}$

6 0

3 years ago

A car accelerates from rest at a constant rate of 2m/s2 for 5s. what is the speed of a car at the end of that time?

Fiesta28 [93]

Good afternoon.

We have:

$\mathsf{V_0 = 0}\\ \mathsf{a = 2 \ m/s^2}\\ \mathsf{t = 5 \ s}$

The function of velocity:

$\mathsf{V = V_0+at}\\ \\ \mathsf{V = 0 + 2t}\\ \\ \mathsf{V = 2t}$

For t = 5 s:

$\mathsf{V = 2\cdot 5}\\ \\ \boxed{\mathsf{V = 10 \ m/s}}$

4 0

3 years ago

Who water rocket starts from rest and roses straight up with an acceleration of 5 m/s until it runs out of water 2.5 seconds lat

Kitty [74]

Answer:

23. 4375 m

Explanation:

There are two parts of the rocket's motion

1 ) accelerating (assume it goes upto h1 height )

using motion equations upwards

$s = ut+\frac{1}{2}*a*t^{2} \\h_1=0+\frac{1}{2}*5*2.5^{2} \\=15.625 m$

Lets find the velocity after 2.5 seconds (V1)

V = U +at

V1 = 0 +5*2.5 = 12.5 m/s

2) motion under gravity (assume it goes upto h2 height )

now there no acceleration from the rocket. it is now subjected to the gravity

using motion equations upwards (assuming g= 10m/s² downwards)

V²= U² +2as

0 = 12.5²+2*(-10)*h2

h2 = 7.8125 m

maximum height = h1 + h2

= 15.625 + 7.8125

= 23. 4375 m

3 0

3 years ago