What belongs in the areas marked X and Y?
O
X: The internal energy of a piston system increases as
heat is added and rises to a cool area
Y: As thermal energy is added to a container, some of
the energy is lost to the environment
X: As thermal energy is added to a container, some of
the energy is lost to the environment
Y: The internal energy of a piston system increases as
heat is added and rises to a cool area
X: A cold spoon placed in hot liquid gets warmer
Y. Thermal energy is converted to light energy
X: Thermal energy is converted to light energy
Y: A cold spoon placed in hot liquid gets warmer

the correct choice is a .

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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 =