Daily NEET MCQ- September 14, 2022 - NEET MCQ

Their magnetic properties cannot be explained easily, as they are more complex. The 5f bands formed due to 5f-5f wave function overlap or to hybridisation with s, p or d electrons. As a result of the band formation, a wide variety of magnetic phenomena may occur.

Actinoids show variable oxidation states because of the smaller energy gap between 5f, 6d and 7s orbitals. Though 3+ is the most stable oxidation state, other oxidation states are possible because of the good shielding of f-electrons.

Actinoids are highly reactive metals especially in the finely divided state. All these metals are attacked by hydrochloric acid but the effect of nitric acid is very small due to the formation of a protective oxide layer on their surface.

If the density of the planet is doubled without any change in its radius, g also gets doubled, because g is proportional to the density of the planet.

Kepler’s second law states that the radius vector drawn from the sun to a planet, sweeps out equal areas in equal intervals of time. It is based on the law of conservation of angular momentum.

In the absence of any external torque, the ball will continue to move at the same speed along the original orbit of space craft.

Two types of calcium channels are present on the membrane of endoplasmic reticulum – IP3 receptors and ryanodine receptors. The latter are present primary in excitable cells like cardiac cells.

Calcium brings about a vast variety of responses in the cell and these are done in conjunction with other proteins that bind to calcium, calmodulin is such a protein found universally in all plants, animals and other eukaryotes.

Paracrine messenger molecules are unstable and cannot travel long distances in the body mostly because they are either degraded by the enzymes or they bind to the extracellular matrix.

Endocrine messengers are also called hormones and operate by the endocrine stimulation. In this pathway of cell signaling the messenger molecules travel through the bloodstream before reaching cell surface receptors that are distant.