Which of the following materials is useful for making molds because it has a low melting point?
a. wood
b. metal
c. clay
d. wax

The correct answer is D. Wax

Explanation:

In chemistry, the melting point of materials or substances refers to the temperature at which a material changes from the solid state to a liquid state which varies according to each material. In the case of wax, its melting point is around 46°C and 68°C which is lower than other materials such as metals that have a melting point between250°C to more than 1000°C depending on the metal or clay that has a melting point around 1780°C. This makes wax one of the materials with the lowest melting point and therefore, one of the most useful materials for making molds.

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.

m=9

step-by-step explanation: