Describe the limitations of using models to represent atoms

Which spectral class does a white dwarf star belong to?

2.26 g of liquid water at 23.5 ◦C was com - pletely converted to ice at 0 ◦C. How much heat was (absorbed/released) by the system during this process?

Explain how matter is not created or destroyed when there are chemical and physical changes.

Uranium-235 has a half-life of 713 million years, while carbon-14 has a half-life of about 5,730 years. Which isotope would be more useful for dating a fossil from Precambrian time?

Which has more energy: yellow or violet light? And why?

The balanced equation below represents the reaction between magnesium metal and hydrochloric acid to produce aqueous magnesium chloride and hydrogen gas. Mg (s) + 2HCl (aq) = = > MgCl2 (aq) + H2 (g) A piece of Mg (s) has a volume of 0.

What is the molarity of a solution prepared by dissolving 33.4 g of sodium chloride in some water and then diluting the solution to a volume of 300.00 mL?

Think about how pressure relates to volume and how gas behavior would change in different volumes. Which of the following will have the largest positive value for Sº? A) 1 mole of helium gas at 1 atm pressure.

Does a reaction stop once it has reached equilibrium? Explain

8 l of water at 19 ∘c are mixed with 1.1 l of water at 47 ∘c in an insulated container. what is the final temperature of the system? express your answer in ∘c