Note the atom of the Oxygen is electrically neutral, meaning it has equal numbers of electrons and protons.
So if it gains 2 electrons, it would have excess of 2 electrons, hence its charge would be -2.
Option B.
Answer:

Explanation:
Required
Which equation represents ohm's law?
Literally, ohm's law implies that current (I) is directly proportional to voltage (V) and inversely proportional to resistance (R).
Mathematically, this can be represented as:

Convert the expression to an equation

Multiply both sides by R to make V the subject


Reorder


<em>Option (a) is correct; Others are not</em>
Answer:
the rocks have the same amount of thermal energy
Answer:

Explanation:
Static friction occurs when an object initially starts at rest. When the surfaces of the materials touch, the microscopic unevenness interlock greatest with each other, causing the most friction out of the three.
During sliding friction, an object is already moving or in motion. The microscopic surfaces still interlock, but because the object is in motion, it has a momentum. Therefore, the magnitude of sliding friction is less than that of static friction.
Rolling friction occurs when an object rolls across some surface. Rather than surfaces interlocking, rolling friction is caused by the constant distortion of surfaces. As it rolls, the surfaces of the object are constantly wrapping and changing. This distortion causes the rolling friction. However, it is much less in magnitude when compared to static or sliding friction.