Answer:
The atomic number is the number over the symbol of the element in the periodic table and the atomic mass the number under it. An isotope is an atom with more or less neutrons than its regular form. a neon atom with mass number of 22 will have 12 neutrons in the nucleus and 10 protons, draw it with its 10 electrons. Two electrons go in the first level of energy and eight in the second. Draw a nucleus with 10 protons and 12 neutrons and an arc with 2 electrons around it and another arc with 8 electrons over the first arc.
Answer:
The answer is <em>e.2</em>
Explanation:
We should make use of Snell's refractive law. The arriving wave has a certain velocity at T in a medium, then instantly it reaches a medium (same composition) at T' where velocity would either decrease or increase.
When the incidence angle is 30 °, and we want to make the refraction angle 90 ° such that no sound passes through the barrier (this would be named total internal refraction), so we want the second medium to be "faster" than in the first.
<em>The steps are in the image attached:</em>
The answer is going be desert.
The kinetic energy K given to the helium nucleus is equal to its potential energy, which is

where q=2e is the charge of the helium nucleus, and

is the potential difference applied to it.
Since we know the kinetic energy, we have

and from this we can find the potential difference: