A student has to create a model of a convex lens. Which property of a convex lens should the student include in the model?
A
The lens spreads light.

B
The lens focuses light.

C
The lens destroys light.

D
The lens reflects light.

A.  The lens spreads light.

Explanation:

The convex lens will converge the light that passes through it. The direction of light will be bend to be closer to the middle point. This is the lens used for the eyeglass that treat people with hypermetropia. That is why the convex lens also called a converging lens or a plus lens. The strength of the convex lens depends on its focal length, index of the material used, and the radius of curvature.

as given the equation is

2al + 6 hcl > 2 alcl3 + 3 h2(g)

as per equation two moles of aluminum reacts with six moles of hcl to give two moles of alcl3 and three moles of hydrogen gas

given: three moles of al are present and 7 moles of hcl

for three moles of aluminum nine moles of hcl will be required

however as 7 moles of hcl are present so the limiting reagent is hcl

hcl is going to decide the number of moles of product formed

when six moles of hcl are present = 3 moles of h2 are formed

when one mole of hcl is present == 3/6 mole sof h2 will be formed

when 7 moles of hcl are present = 3 x 7/ 6 moles of h2 will be formed = 3.5 moles of h2