Find the mass of 3.90*10^23 molecules of carbon dioxide

28.5 g

Explanation:

1 mole of every substance contains Avogadro's number of particles and weighs same as it's molecular weight.

Here 1 mole of contains molecules of and it weighs

molecules weigh 44g

molecules weigh =

                                                          = 28.5g

a) the particles of the chair are strongly held together.

while cooking a piece of 1/2 pound beef steak, a cast iron pan (2.4kg in weight) was heated 260 celsius.