For atoms in the periodic table, the given mass number is the sum of the number of the protons (also called the atomic number) and the number of the neutrons inside its nucleus. Mathematically,
mass number = atomic number + number of neutrons
Substituting,
39 = 19 + n
n = 39 - 19 = 20
Therefore, the answer is not found in the choices.
<u>Displacement</u> is the difference between final position and initial position.
<u>Momentum</u> is the quantity of motion contained by an object.
- It is the product of <em><u>mass and velocity.</u></em>
In series circuit, Req = R₁ + R₂ + R₃ + ···
In parallel circuit,
<h3>Q7.</h3>
total resistance in the upper branch = R₂ + R₃ = R₂ + 2
R₂ + 2 = 12
R₂ = 10Ω
<h3>Q8.</h3>
Req = 1.7Ω