Chemical or physical change? and what made you think such?

Which of these properties, used alone, would be least useful in identifying most minerals? a. color b. luster c. streak d. density

Which part of a feedback mechanism is able to monitor the conditions outside of cells and usually uses nerve cells to relay this information to an intergrating center

Which type of orbits are found in the principal energy level n = 2 a - s b - s, f c - s, d d - s, p e - s, p, d