Which of the following best describes a physical change?* A. When a new element is created.

B. When molecules combine to form a compound.

C. When elements combine to form a molecule.

D. When the size, shape, or state of matter changes.

Man i dont know this answer

Adialysis unit requires 78.5 l of water.the estimated digit is 5. 

Mars contains iron oxide in its crust

Heat capacity = mcδtheat capacity = 2.676×10^3 j ..the heat capacity given is for 7.00 g of kcn,potassium cyanide which is equal to 0. mole of mole = mass  ÷ mr of kcn is 7  ÷ 65 =0.therefore: 0. of kcn liberates 2.676×10^3 j of heat1 mole   (2.676×10^3    ÷  0.107 )  × 1 =do the calculation to obtain 25009 j = 25kj