Ask question

Ask question

All categories

2 years ago

9

Which of the following gives good evidence for the particle nature of EM radiation?

2 answers:

Marat540 [252]2 years ago

7 0

Answer:

1. Which of the following gives good evidence for the particle nature of EM radiation?

-photoelectric effect

2.Which of the following gives good evidence for the wave nature of EM radiation?

-interference patterns

3.When studying the photoelectric effect, which parameters did scientists think were relevant for electrons to be released or not in both the wave and particle models?

-frequency and intensity for the wave model; frequency only for the particle model

4.The image represents the gaps between allowed energy levels for electrons. Which model best describes this phenomenon?

-the particle model because the arrows represent discrete particle-like jumps

5. Which subatomic particle has the smallest mass?

-electron

6.The atomic number on the periodic table refers to the number of _____ within an atom.

-protons or electrons

7.Considering that an up quark has a charge of +23 and a down quark has charge of −13, which of the following represents the correct quark combination for a proton?

-2 up, 1 down

8. If an atom gives off electromagnetic radiation with a frequency of 2.0×1015s−1, what is the radiation’s energy?

-1.3×10−18 J

9. A nuclide of phosphorus 3015P decays into a nuclide of silicon 3014Si. In order to satisfy charge conservation and lepton number conservation the other products must be __________.

-a positron and an antineutrino

10.In a gamma decay process __________.

-a parent nuclide was in an excited state

11.Nuclide X has a higher rate of decay than nuclide Y. Based on this information, which of the following statements must be true?

- Nuclide Y has a larger half-life than nuclide X.

12. A microwave has a typical wavelength of about 0.1 meter. What is the comparable wavelength of a radio wave?

-Greater than 0.1 meter.

13.A satellite phone can be used to place a call from virtually anywhere in the world. What type of wave does the satellite phone likely transmit to the satellite orbiting above Earth?

-radio wave

14.The speed of a light wave c is related to its wavelength λ and its frequency f by c=λf. If the speed of light is 3×108 meters/second and the wavelength of an infrared wave used in a remote control is 7×10−9 meters, then what is its frequency?

-4×1016 Hz

15.In what way does a lead apron protect human cells from X-rays?

-In what way does a lead apron protect human cells from X-rays?

16.Why are children more susceptible to the effects of ionizing radiation?

-They have many growing cells that can easily have DNA damaged.

17.Which statement is correct about the half-lives of radioactive elements?

-The half-lives of radioactive elements vary from fractions of a second to billions of years.

18.Source A has a half-life of 10 million years, and source B has a half-life of 5 million years. After 10 million years, what percent of each source remains?

-50% of source A and 25% of source B

19.The probability that a randomly chosen nucleus in a radioactive sample will have decayed in a given time is 96.875%. How many half-lives has the sample experienced?

-5

20.A radioactive sample starts with 800,000 undecayed nuclei. After 12 hours, 700,000 of the nuclei have decayed. What is the half-life of the sample?

- 4 hours

21.How did the development of electrical signals sent through wires change communication?

-Signals could be sent anywhere a wire could reach and no longer were restricted to line of sight.

22. Essay

23.Essay

24.Essay

25.Essay

26.Essay

Explanation:

100% correct

k0ka [10]2 years ago

6 0

One phenomenon which well presents the idea of wave particle duality is the photoelectric effect.

<h3>What is wave particle duality?</h3>

The term wave particle duality has to do with the fact that a wave can behave sometimes as a wave and sometimes as a particle. This was well established by the work of De Broglie.

One phenomenon which well presents the idea of wave particle duality is the photoelectric effect.

Learn more about wave particle duality:brainly.com/question/14953274

#SPJ1

You might be interested in

I need answers and solvings to these questions

den301095 [7]

1) The period of a simple pendulum depends on B) III. only (the length of the pendulum)

2) The angular acceleration is C) $15.7 rad/s^2$

3) The frequency of the oscillation is C) 1.6 Hz

4) The period of vibration is B) 0.6 s

5) The diameter of the nozzle is A) 5.0 mm

6) The force that must be applied is B) 266.7 N

Explanation:

1)

The period of a simple pendulum is given by

$T=2\pi \sqrt{\frac{L}{g}}$

where

T is the period

L is the length of the pendulum

g is the acceleration of gravity

From the equation, we see that the period of the pendulum depends only on its length and on the acceleration of gravity, while there is no dependence on the mass of the pendulum or on the amplitude of oscillation. Therefore, the correct option is

B) III. only (the length of the pendulum)

2)

The angular acceleration of the rotating disc is given by the equation

$\alpha = \frac{\omega_f - \omega_i}{t}$

where

$\omega_f$ is the final angular velocity

$\omega_i$ is the initial angular velocity

t is the time elapsed

For the compact disc in this problem we have:

$\omega_i = 0$ (since it starts from rest)

$\omega_f = 300 rpm \cdot \frac{2\pi rad/rev}{60 s/min}=31.4 rad/s$ is the final angular velocity

t = 2 s

Substituting, we find

$\alpha = \frac{31.4-0}{2}=15.7 rad/s^2$

3)

For a simple harmonic oscillator, the acceleration and the displacement of the system are related by the equation

$a=-\omega^2 x$

where

a is the acceleration

x is the displacement

$\omega$ is the angular frequency of the system

For the oscillator in this problem, we have the following relationship

$a=-100 x$

which implies that

$\omega^2 = 100$

And so

$\omega = \sqrt{100}=10 rad/s$

Also, the angular frequency is related to the frequency $f$ by

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

Therefore, the frequency of this simple harmonic oscillator is

$f=\frac{10}{2\pi}=1.6 Hz$

4)

When the mass is hanging on the sping, the weight of the mass is equal to the restoring force on the spring, so we can write

$mg=kx$

where

m is the mass

$g=9.8 m/s^2$ is the acceleration of gravity

k is the spring constant

x = 8.0 cm = 0.08 m is the stretching of the spring

We can re-arrange the equation as

$\frac{k}{m}=\frac{g}{x}=\frac{9.8}{0.08}=122.5$

The angular frequency of the spring is given by

$\omega=\sqrt{\frac{k}{m}}=\sqrt{122.5}=11.1 Hz$

And therefore, its period is

$T=\frac{2\pi}{\omega}=\frac{2\pi}{11.1}=0.6 s$

5)

According to the equation of continuity, the volume flow rate must remain constant, so we can write

$A_1 v_1 = A_2 v_2$

where

$A_1 = \pi r_1^2$ is the cross-sectional area of the hose, with $r_1 = 5 mm$ being the radius of the hose

$v_1 = 4 m/s$ is the speed of the petrol in the hose

$A_2 = \pi r_2^2$ is the cross-sectional area of the nozzle, with $r_2$ being the radius of the nozzle

$v_2 = 16 m/s$ is the speed in the nozzle

Solving for $r_2$ , we find the radius of the nozzle:

$\pi r_1^2 v_1 = \pi r_2^2 v_2\\r_2 = r_1 \sqrt{\frac{v_1}{v_2}}=(5)\sqrt{\frac{4}{16}}=2.5 mm$

So, the diameter of the nozzle will be

$d_2 = 2r_2 = 2(2.5)=5.0 mm$

6)

According to the Pascal principle, the pressure on the two pistons is the same, so we can write

$\frac{F_1}{A_1}=\frac{F_2}{A_2}$

where

$F_1$ is the force that must be applied to the small piston

$A_1 = \pi r_1^2$ is the area of the first piston, with $r_1= 2 cm$ being its radius

$F_2 = mg = (1500 kg)(9.8 m/s^2)=14700 N$ is the force applied on the bigger piston (the weight of the car)

$A_2 = \pi r_2^2$ is the area of the bigger piston, with $r_2= 15 cm$ being its radius

Solving for $F_1$ , we find

$F_1 = \frac{F_2A_1}{A_2}=\frac{F_2 \pi r_1^2}{\pi r_2^2}=\frac{(14700)(2)^2}{(15)^2}=261 N$

So, the closest answer is B) 266.7 N.

Learn more about pressure:

brainly.com/question/4868239

brainly.com/question/2438000

#LearnwithBrainly

5 0

3 years ago

Which actions are evidence that a chemical reaction has occurred? Check all that apply. a change in color the formation of a pre

NeTakaya

Answer:

a change in color
the formation of a precipitate
the formation of bubbles

Explanation:

In a chemical reaction, there is always a rearrangement of atoms within the molecules of reactants to form new products. Such a change is different from changes in the physical form of molecules, e.g. shape.

Thus, according to this criteria, only three options are correct in the given question. A change in color is definitely an indication of chemical reaction because the emission of light before and after cannot be changed unless molecules are rearranged to form a new chemical. Likewise, precipitates form when a reaction takes place between chemically dissolved molecules to form less or not dissolvable compounds. In the end, the configuration of bubbles also indicates that the reaction has taken place because new gases are being released.

On the other hand, change in shape is a physical change because the composition doesn't need to also been changed. An example is the ice formation from water. Same is the case with "change of clear liquid to cloudy" because the addition of non-reactive substances could change the nature of liquid to cloudy however the reaction doesn't need to have taken place.

8 0

3 years ago

Read 2 more answers

Explain you own words why energy is considered to be naturals money. Give an example to support your explanation

max2010maxim [7]

Answer:

because we naturally use energy everyday in everyway , energy is also a bill for instance you electric bill used by energy

Explanation:

8 0

3 years ago

Novosadov [1.4K]

Answer:

an inverse relationship

7 0

3 years ago

1. A perspex box has a 10 cm square base and contains water to a height of 10 cm. A piece of rock of mass 600g is lowered into t

AnnZ [28]

Answer:

(a) The volume of water is 100 cm³

(b) The volume of the rock is 20 cm³

(c) The density of the rock is 30 g/cm³

Explanation:

The given parameters of the perspex box are;

The area of the base of the box, A = 10 cm²

The initial level of water in the box, h₁ = 10 cm

The mass of the rock placed in the box, m = 600 g

The final level of water in the box, h₂ = 12 cm

(a) The volume of water in the box, 'V', is given as follows;

V = A × h₁

∴ The volume of water in the box, V = 10 cm² × 10 cm = 100 cm³

The volume of water in the box, V = 100 cm³

(b) When the rock is placed in the box the total volume, $V_T$ , is given by the sum of the rock, $V_r$ , and the water, V, is given as follows;

$V_T$ = $V_r$ + V

$V_T$ = A × h₂

∴ $V_T$ = 10 cm² × 12 cm = 120 cm³

The total volume, $V_T$ = 120 cm³

The volume of the rock, $V_r$ = $V_T$ - V

∴ $V_r$ = 120 cm³ - 100 cm³ = 20 cm³

The volume of the rock, $V_r$ = 20 cm³

(c) The density of the rock, ρ = (Mass of the rock, m)/(The volume of the rock)

∴ The density of the rock, ρ = 600 g/(20 cm³) = 30 g/cm³

8 0

3 years ago