The mass of iron block is 500 g. The amount of energy required to melt the iron block needs to be calculated. Melting means conversion of solid to liquid thus, heat of fusion is used which is 247 J/g.
From heat of fusion, 247 J of energy is released by melting 1 g of iron block. Thus, the amount of heat released by melting 500 g of iron rod will be:
H= 247 J/g× 500 g=1.23×10^{5}
Hence, option B is correct.
16.00 g -------------- 6.02x10²³ atoms
?? g ----------------- 6.022x10²³ atoms
16.00 x (6.022x10²³) / 6.02x10²³ =
=> 16 g
Answer : Both solutions contain 
molecules.
Explanation : The number of molecules of 0.5 M of sucrose is equal to the number of molecules in 0.5 M of glucose. Both solutions contain 
molecules.
Avogadro's Number is 
= 
which represents particles per mole and particles may be typically molecules, atoms, ions, electrons, etc.
Here, only molarity values are given; where molarity is a measurement of concentration in terms of moles of the solute per liter of solvent.
Since each substance has the same concentration, 0.5 M, each will have the same number of molecules present per liter of solution.
Addition of molar mass for individual substance is not needed. As if both are considered in 1 Liter they would have same moles which is 0.5.
We can calculate the number of molecules for each;
Number of molecules = 
;
∴ Number of molecules = 
which will be = 
Thus, these solutions compare to each other in that they have not only the same concentration, but they will have the same number of solvated sugar molecules. But the mass of glucose dissolved will be less than the mass of sucrose.
1. Answer: C. The objects' temperatures have both changed by the same amount.
Explanation:
An object is said to be in thermal equilibrium when the objects have attained same temperature. Heat transfer from hotter object to colder one in contact takes place until the temperature of the two are equal. It is not necessary that the temperature of both the objects changes by same amount. After attainment of thermal equilibrium, the temperature of the objects stop changing and the tiny particles of the object move at the same rate.
Hence, the objects' temperatures have both changed by the same amount. is not necessarily true for two objects in thermal equilibrium.
2. Answer: C. Objects are made of tiny particles, and their motion depends on the temperature.
Explanation:
Kinetic theory of heat states that the kinetic energy of constituent particles determine the temperature of the object. The statement that best explains this is Objects are made of tiny particles, and their motion depends on the temperature.
