The closest answer is
Alpha - mass of 4 and charge of +2; beta - no mass and charge of -1; gamma - no mass and no charge (consists of energy)
It’s not exactly correct because a beta particle has the (small) mass of an electron (also the positron). All other choices are way off, I’d go with this one.
Answer:
Selenium is a semiconductor
Explanation:
Selenium is a semiconductor.
Elements in the column IV and VI of the periodic table are referred to as Semiconductor.
Selenium lies in the column VI along with Tellurium
Some other elements of the column IV are silicon, germanium, and tin
To solve the exercise it is necessary to take into account the concepts of wavelength as a function of speed.
From the definition we know that the wavelength is described under the equation,

Where,
c = Speed of light (vacuum)
f = frequency
Our values are,


Replacing we have,



<em>Therefore the wavelength of this wave is
</em>
The answer is going be desert.
Answer:
18.2145 meters
Explanation:
Using the conservation of momentum, we have that:

m1 = m1' is the mass of the astronaut, m2=m2' is the mass of the satellite, v1 and v2 are the inicial speed of the astronaut and the satellite (v1 = v2 = 0), and v1' and v2' are the final speed of the astronaut and the satellite. Then we have that:


The negative sign of this speed just indicates the direction the astronaut goes, which is the opposite direction of the satellite.
If the astronaut takes 7.5 seconds to come into contact with the shuttle, their initial distance is:
