Answer: 2; 3
For each FADH2 that supplies electrons to the electron transport system, 2ATPs are synthesized. For each NADH that supplies electrons to the electron transport system, 3 ATPs are synthesized.
Explanation:
Both FADH2 and NADH are you reducing equivalents in that they give off electron in terms of hydrogen atom or a hydride ion.
Thus, in the inner membrane of the mitochondria where electron transport occurs, FADH2 gives off its hydride ion yielding 2 ATP molecules; while NADH gives off its hydride ions to yield 3 ATP molecules
The Earth and Moon compare in terms of gravitational force as Earth's gravitational force is stronger than the Moon's.
Option A
<u>Explanation:</u>
According to universal law of gravity, the gravitational force is the attractive force between two objects separated by a distance. The magnitude of gravitational force is directly proportional to the product of masses of the objects and inversely proportional to the square of the distances between them.
In this case, the gravitational force acting on us due to Earth will be considered due to the mass of Earth as the mass of Earth is very large compared to our mass.

So as the mass of the Earth is greater than the mass of the moon, so the gravitational force of Earth will be stronger than that of Moon.
Answer: A.
Explanation: When a chlorine atom gains an electron, its outermost principal energy level achieves an octet. In this case, the ion has the same outermost shell as the original atom, but now that shell has eight electrons in it.
Because it’s time consuming and money consuming to observe from space so models are required
Answer:
Sometimes molecules cannot move through the cell membrane on their own. These molecules need special transport proteins to help them move across the membrane. Facilitated diffusion is the diffusion of substances with the help of transport proteins in the plasma membrane. These special proteins are called channel proteins or carrier proteins, and they are attached to the cell membrane. In fact, they go through the cell membrane, from the inside of the cell to the outside. Facilitated diffusion is used for molecules that cannot diffuse rapidly through cell membranes on their own, even when the molecules are moving from high to low concentration areas. An example is the sugar plants and animals use for energy, called glucose. Even though facilitated diffusion involves transport proteins, it is still passive transport because the solute is moving down the concentration gradient so it does not require the use of cellular energy.