Question

pure sodium metal explodes when it makes contact with water. in its natural state, chlorine is a deadly, poisonous gas. when these two chemicals combine, they form a harmless, white powder known as sodium chloride or table salt. which of the following statements does this information support?
a. when substances are chemically combined, the properties of the new substances that are formed are the same as the properties of the original substances.

b. the properties of substances change during chemical reactions but then later go back to their original condition.

c. heat must be added in order to change the chemical properties of substances.

d. when substances are chemically combined, the properties of the new substances that are formed are often different from the properties of the original substances.

Explanation:

The example shows sodium (explosive with water) and chlorine (deadly gas) chemically combining to form sodium chloride (harmless table salt). This demonstrates that the new substance has properties distinct from the original substances. Option A is incorrect because properties differ. Option B is wrong as properties don’t revert. Option C is unsupported—no heat addition is mentioned. Option D aligns with the observation.

Answer:

D. When substances are chemically combined, the properties of the new substances that are formed are often different from the properties of the original substances.