The molecular mass of sodium = 23g
One mole of sodium consists of 23 g of sodium
One mole consists of 1 Avagadro(6.022 x 10^23 molecules) number of molecules
Therefore 23 g consists of 6.022 x 10^23 molecules of Sodium.
Hence 7.45 x 10^3 g of Sodium will consist of x no of molecules of sodium.
x no of molecules =
(7.45 x 10^3 g/23 g) x (6.022 x 10^23)
=1950.6 x 10^ 23 molecules (atoms).
Elements present in group 18 are known as noble gases. The outermost shell of these elements are completely filled.
18 is the answer
Firstly, the density of any substance is represented by the mass (amount of matter) as divided by the volume(amount of space). According to external websites, the mass of a penny is 2.5 grams.However, the volume of a penny is .35cm to the power of 3 (due to the thickness of the penny being extremely minimal.Thus the amount of density is extremely little). Therefore, the density of a penny is 0.875 g/cm cubed (dimensional analysis).As for an invention that could be used, that is possible with the usage of a series of measurements that can both calculate mass and volume and directly allocate that to attain density
Answer:
The temperatures of the objects must be different
Explanation:
if heat is flowing between two objects, then the objects must be at different temperatures.