You have 1.2 x 10^25 particles of NiCO3. How many grams are present?

c. heat could easily travel through the molecules in the air and escape/enter the flask. removing the air slows down the heat transfer.  

plants need sunlight, water, and carbon dioxide to make food. plants use the raw materials of water, nutrients they absorb from soil, and carbon dioxide to make sugars the plant can use. energy from the sun and chlorophyll are also needed.

level 4 to level 2 : ))