In a science experiment, Javi concludes that a chemical reaction has occurred. What evidence would support this conclusion? A
a substance melted

B
a substance's color and odor changed

C
a substance's mass and texture changed

D
new atoms were created

B) a substance's color and odor changed        Explanation: A signal that a chemical change has occurred is when its odor (its smell) or its appearance has changed.

that correct answer is The product is not poisonous or odorous like chlorine, and it’s no longer a metal like sodium. It does not have the same properties as either reactant. Also, the white “dust” in the video indicates that a reaction has taken place.

Explanation:

i take the test

a graduated cylinder.

explanation:

the number of valence electrons for each molecule or ion is shown beneath the structure. remember hydrogen will not have more than two electrons. this hydrogen is part of a covalent bond (sharing two electrons). a double bond here would cause hydrogen to share four electrons with phosphorus.