2 When enough heat is added to liquid water, it boils, and bubbles of water vapor rise to the surface and into the air. Which type of change is this and why? A. a chemical change, because gas is produced B. a chemical change because heat is produced C. a physical change because the identity of the substance changes D. a physical change because the substance changes state.3 4. A sample of aluminum has a volume of 3.0 cm3 and a mass of 8.1 g. Which is the density of aluminum?
A. 2.7 g/cm3
B. 5.1 g
C. 11.l cm3
D. 24.3 g/cm3

I only need two question fast

In the first paragraph, name a theme of Paul Laurence Dunbar's poem "Sympathy," and explain how it develops, citing specific examples

Explanation:

answer: the figure is attached herewith.

step-by-step explanation:   we are given to sketch a unit circle and label the terminal points corresponding to

in the attached figure, we have drawn a unit circle, with centre at o(0,0) and radius 1 unit. we have labelled the points a, b, c, d and e corresponding to the angles below

∠aox = 60°,

∠box = 120°,

∠cox = 180°,

∠dox = 240°,

∠eox = 300°.

and the coordinates are a(0.5,1), b(-0.5,1), c(-1,0), d(-0.5,-1) and e(0.5,-1).

thus, the answer is complete.

> b takes place in the gas phase in an isothermal tubular reactor. the feed is one mole of a per one mole of c, an inert. the entering temperature and pressure are 427°c and 10 atm, respectively. the gas constant r = 0.08206 atm · l/mol · k.