Whitch of the following are physical changes?

Rusting

Souring

Melting

Boiling

Freezing

You are given 230 grams of a substance with a half-life of 0.75 years. How much will remain after 3 years?

What is the density of a substance that has a mass of 55.4 g and a volume of 10 cm3?

23492u undergoes alpha decay. what is the atomic number of the resulting element. express your answer numerically as an integer.

Whats the si unit chemist use to measure the amount of an element substance?

Meaning of particle motion

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