QUES: The sea 5 is darker than the land 6 on the visible image because it absorbs more solar radiation

correct the punctuation.

CORRECTED: The sea (5) is darker than the land (6) on the visible image, because it absorbs more solar radiation.

QUES: The medallion with the Polar Bear of Greenland

correct the punctuation.

CORRECTED: The medallion with the Polar Bear of Greenland.

QUES: The result may provide the basis for consideration of substituting certain chemicals in compounded products

correct the punctuation.

CORRECTED:
The result may provide the basis for consideration of substituting certain chemicals in compounded products.