PLEASE HELP
The image characteristics are...

According to the question, the object is placed at 2F

The ray diagram is shown in the figure attached.

According to the figure:

Object AB is at 2F₁

First, we draw a ray parallel to principal axis.

So, it passes through focus after refraction.

We draw another ray which passes through optical center.

So, the ray will go through without any deviation.

Where both refracted rays meet is point A' and the image formed is A'B'

This image is formed at 2F₂

We can say that:

luster is not a good characteristic to use by itself because luster is the property of minerals that indicates how much the surface of a mineral reflects light. the luster of a mineral is affected by the brilliance of the light used to observe the mineral surface.

it is given that trillions of microbes make up to 1% to 3% of the body mass.

let's take average of this percentage: 2%

consider the average mass of the human body as 70 kg.

then, trillions of microbes would have mass  

therefore, 100 trillion micro-organisms would weigh:

this is an approximate value and could change depending on the mass of the human body and percentage of the microbes present in it.

average mass per microorganism =