Is a chemical property of matter.
a. color
b. hardness
c. melting point
d. chemical reactivity

it is chemical reactivity (D)

Explanation:

it is because chemical properties are properties that can be measured and observed only when matter undergoes a change to become an entirely different kind of matter.Which they include Chemical reactivity,flammable,and the ability to rust.And Chemical reactivity is the ability of matter to react chemically with other substances.

t2 equal the displacement of the particle over the same time period if t2> t/2? hint: consider a sine wave starting at t1=0, then consider a closing wave starting at t1=0, for your explanatio

igneous rocks also form where plates converge. the subducting plate melts as it sinks into the crust of the earth, and the melt rises into the overriding plate forming volcanoes. metamorphic rocks are formed mainly in the lithosphere, wherever there is high pressure and high temperature. -woods