Answer:
Proton, neutron, electron
Explanation:
The atom consists of a nucleus, where almost all the mass is concentrated, and electrons orbiting around the nucleus.
The nucleus consists of two types of particles:
- Proton: it has a mass of
, and a positive electric charge of +e (
)
- Neutron: it has a mass of
, and it has no electric charge
The third particle that makes an atom is the electron, that orbit around the nucleus:
- Electron: it has a mass of
, and it has a negative electric charge of -e (
)
An excited atom can return to its ground state by absorbing electromagnetic radiation is false about the electromagnetic radiation.
Option B
<u>Explanation</u>:
In the scope of modern quantum theory, the term Electromagnetic radiation is identified as the movement of photons through space. Almost all the sources of energy that we utilize today such as coal, oil, etc are a product of electromagnetic radiation which was absorbed from the sun millions of years ago.
Various properties of electromagnetic radiations are a directly proportional relationship between the energy and the frequency, Inverse proportionality between frequency and the wavelength, etc. Hence, we can conclude that an "excited atom" can never return to its ground state by assimilating electromagnetic radiation and the 2nd statement is false.
The atomic number is the number of protons. So, you can subtract the atomic number from the mass number to find the number of neutrons.
I hope this helps! :)
Answer:
22.2 W
Explanation:
First of all, we calculate the work done by moving the wagon, using the formula:

where
F = 20 N is the magnitude of the force
d = 1000 m is the displacement of the wagon
is the angle between the direction of the force and of the displacement (assuming the force is applied in the direction of motion)
Substituting, we find

Now we can find the power generated, which is equal to the ratio between the work done and the time taken:

where
W = 20,000 J
t = 15 min = 900 s
Substituting,

And the same value in Joules/second (remember that 1 Watt = 1 Joule/second)