Which of the following provides evidence that a chemical change has taken place? a). the original substance can be recovered by physical processes b). a gas is formed when tow liquids are mixed c). some pieces of substances get smaller or disappear d). one substance dissolves in another

Answer : Option B) A gas is formed when two liquids are mixed.

Explanation : In this example a gas is forming as a result of mixing two liquids, so, changing of state can be clearly noticed, also there is a new substance which is produced and the reaction is also irreversible (i.e. it cannot be easily recovered to the starting reactants by any physical process). Hence, Option B is correct answer.

a: 45.9 meters

b: 4.29 seconds

step-by-step explanation:

a: h(t)=1/2(-9.8)(3)^2+0(3)+90

h(t)=-4.9(3)^2+90

h(t)=-44.1+90

h(t)=45.9 meters

b: 0=1/2(-9.8)(t^2)+0t+90

0=-4.9t^2+90

-90=-4.9t^2

18.37=t^2

t=4.29 seconds

in the second question, the numbers aren't exact, but they're a close approximation.

c)red bank

explanation:

red bank is a borough in monmouth county, new jersey, incorporated in 1908 and located on the navesink river, the area's original transportation route to the ocean and other ports.