Why does the moon have phases? What are the four main phases of the moon? How long does it take to change from one to another?

What makes a nucleus unstable

1. what is volume? a) half of the density of a substance b) the amount of matter in a substance c) twice the amount of mass of substance d) the amount of space a substance takes up 2.

Which of the following is NOT soluble in water? A) NaCl B) KBr C) CH3CH2OH D) HCl E) C6H6 and how do i know?

Which is an example of a condition in which homeostasis is maintained using a negative feedback loop? A. low blood glucose B. break or tear in blood vessel wall C. death of a small area of heart tissue D.

Which extraction procedure will completely separate an amide from the by-product of the reaction between an amine and excess carboxylic acid anhydride? A) Add 0.1M NaOH (aq) to quench unreacted anhydride.

The molar mass of water (H2O) is 18.02 g/mol. Yun needs 0.025 mol H2O for a laboratory experiment. She calculates that she needs 72.0 g H2O for the experiment. Yun's calculation was incorrect because she set up her unit conversion incorrectly.

I'm doing isotope homework and I need the find the number of protons, neutrons, and electrons first one is chromium-58 and chromium-63

Trisha and her lab partner were conducting a variety of experiments to produce gases: hydrogen, oxygen, and carbon dioxide. In one experiment, they added a piece of magnesium ribbon to 10 milliliters of hydrochloric acid.

what mass of magnesium is required to react with excess nitrogen to produce 0.500 mol magnesium nitrade

Silver chromate is sparingly soluble in aqueous solutions. the ksp of ag2cro4 is 1.12 * 10-12 m3. what is the solubility (in mol/l) of silver chromate