11. Which of the following is an irreversible physical change?
a, melting a piece of lead
b sharpening a pencil
c dissolving sugar into water
d boiling water

24 points and brainliest to anyone who can answer under 10 minutes with best ! the table below shows the role of different substances during photosynthesis. substance role during photosynthesis glucose stores chemical energy water combines with glucose to form carbon dioxide chlorophyll traps sunlight which of the following statements would correct one of the roles listed in the table? glucose combines with carbon to form water. chlorophyll reacts with light to produce carbon dioxide. water combines with carbon dioxide during photosynthesis. chlorophyll stores chemical energy needed for photosynthesis.

Apump contains 0.5 l of air at 203 kpa. you draw back on the piston of the pump, expanding the volume until the pressure reads 50.8 kpa. what is the new volume of the air pump

Consider a culture medium on which only gram-positive organisms such as staphylococcus aureus colonies can grow due to an elevated nacl level. a yellow halo surrounds the growth, indicating the bacterium fermented a sugar in the medium, decreasing the ph as a result and changing the color of a ph indicator chemical. this type of medium would be referred to as a differential and enrichment culture.