What is a pure substance that cannot be chemically broken down into simpler substances?

How are repetition repetition and replication alike and different

An aspirin tablet contains 81.0 mg of aspirin, which has the molecular formula, c9h8o4.

What is the mass defect of lithium? Assume the following: Atomic number of lithuim = 3 Atomic mass of lithuim = 7.0144 atomic mass units. Mass of 1 proton = 1.0073 atomic mas units. Mass of 1 neutron = 1.0087 atomic mass units.

During the winter months, the groundwater in an area freezes, the rivers freeze, and there is little sunlight available. Which of the following processes would allow plants to survive the winter conditions? A. hibernation B. dormancy C. migration D.

Write a balanced chemical equation for the reaction of gaseous nitrogen dioxide with hydrogen gas to form gaseous ammonia and liquid water Express your answer as a chemical equation. Identify all of the phases in your answer.

What is unique about the way that transition metals form compounds? a. They don't form compounds c. They can form bonds with the electrons in the two outer-most shells b. They are the most reactive d. They can donate all of their electrons

What prompted rutherford to do the alpha particle scattering experiment?

How many moles of hydrogen would be required to produce 5.0 mol of water?

What is the biggest difference between an exothermic and endothermic process? A. The direction of energy flow. B. The amount of energy transferred. C. The type of energy being transferred. D. The speed with which energy is transferred.

The mass of 1 mol of chromium (atomic mass 51.996 amu) is