What do scientists mean when they speak of a phase or state of matter?

Is cloud seeding a physical or chemical change

Why is it important to perform the reagent tests last?

Which element could not form in the sun and would have to be formed in a supernova? a. hydrogen (atomic number 1) b. helium (atomic number 2) c. oxygen (atomic number 8) d.

Which energy level has the least energy

The four isotopes of lead are shown below, each with its percent by mass abundance and the composition of its nucleus. using these data, calculate the approximate atomic mass of lead.

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

What do you think 1,5-pentanedithiol C5H12S would smell like