Answer:

Explanation:
We want to find the density. The formula is mass over volume.

The mass is 500 kilograms. The volume is 0.026 cubic meters.

Substitute the values into the formula.

Divide.

This is just about equal to 19,320 kg/m³, so choice A is correct.
Metals are good conductors of heat and electricity
Metals are good conductors due to presence of free electrons
They act as carrier to conduct heat or electricity.
So
Aluminum spoon will heat up as it is of metal
Iron spoon will heat up as it is of metal
Silver spoon will also heat up as it is of metal
Wood is a bad conductor of heat. It is an insulator
Wood has air space or pockets in its structure which makes it a bad conductor (it cannot conduct heat)
So a wooden spoon will be stay coolest as it is an insulator
Answer: Thus 0.724 mol of
are needed to obtain 18.6 g of 
Explanation:
To calculate the moles :

According to stoichiometry :
2 moles of
are produced by = 1 mole of 
Thus 1.09 moles of
will be produced by =
of 
But as yield of reaction is 75.6 %, the amount of
needed is =
Thus 0.724 mol of
are needed to obtain 18.6 g of 
0.001 would be the smallest.
Good Luck! :)