The is a diffuse set of neurons in the core of the brain stem that screens incoming sensory information and arouses the cortex.

the answer is: they occur when the sun, moon, and earth are aligned. in spite of their name, these tides occur twice a year in the spring and fall.

a and b

answer: zinc is the substance which has a volume of 1.38 .

density is defined as the mass of an object per unit volume.

it can be calculated by dividing mass of a substance by its volume i.e.

si unit of density is kg per cubic meter and cgs unit of the same is gram per cubic centimeter.

now from the given data volume can be calculated by the formula .

hence, the volume of aluminium will be = which comes out to be 1.703 .

similarly, volume of zinc, chromium, and nickel will be 1.378 , 0.869 , and 0.356 respectively.