People have developed models of the universe for thousands of years. Identify two observations that a model of the universe would need to explain in order to be useful

What is the molarity of 5.39 grams of CaCl2 dissolved in 609 mL of water? (molar mass = 110.98 g/mol)

In Part 4, students flame tested the gas produced in the reaction. What happened when a flame was held in the inverted the test tube above the metal reacting with hydrochloric acid

What type of potential energy is stored in the sugars produced by plants?

When will the population of prey increase greatly? A) when the population of predators is low B) when the population of predators is moderate C) when the population of predators is high D) when the population of predators swells E) when the

Predict the product of the reaction between toluene and bromine in presence of iron. Draw arrow-pushing mechanism for the major products. anything would be appreciated because I have no idea how to start this!

What is the ratio of effusion rates of krypton and neon at the same temperature and pressure?

Balance the following equation _NaOH (aq) + _HNO3 (aq) > _NaNO3 (aq) + _H2O (1)

Researchers discovered a subatomic partial while working with the cathode ray tube the particle is known as

An electrochemical cell is constructed such that on one side a pure nickel electrode is in contact with a solution containing Ni2 + ions at a concentration of 2 * 10-3 M.

The lines in an element's atomic spectrum result from electron spins going in opposite directions. energy that is spread out among an atom's electrons. electrons moving from a lower to a higher energy level.