Which of the following describes a chemical change?

a. ethanol boils when heated.

b. ethanol has a high heat capacity.

c. ethanol can be produced by the fermentation of grapes.

d. ethanol is a clear

Electron configurations are like an address because?

Manganese dioxide (MnO2 (s), Hf = - 520.0 kJ) reacts with aluminum to form aluminum oxide (AI2O3 (s), Hf = - 1699.8 kJ/mol) and manganese according to the equation below. What is the enthalpy of the reaction?

subtract the mass of the filter paper (0.27 g) from the mass of the paper and copper (0.98 g). Record the difference in the data table as the amount of copper.

A solute will probably dissolve best in a A. hot solvent B. cold solvent C. room temperature solvent D. temperature does not affect solubility

What type of bond (covalent, polar covalent or ionic) does aspirin have?

The van der Waals forces of attraction between molecules always become stronger as molecular size 1) decreases, and the distance between the molecules increases 2)) increases, and the distance between the molecules decreases 3) decreases, and the

Which civilization formed a confederation thay may have impacted the us government A. Powhatan B. Algonquian C. Iroquois D. Anasazi

Jasmine breathed against the window pane and noticed that her breath made a spot on it from the water vapor in her breath. Which stage of the water cycle does this show? A. precipitation B. evaporation C. condensation D. transpiration

Amber has developed a line of organic lotions and handmade soaps with unique, herb-based scents and a touch of bee balm. She plans to sell these products to the wealthy residents of a nearby resort town.

Two pure elements react to form a compound. One element is an alkali metal, X, and the other element is a halogen, Z. Which of the following is the most valid scientific claim that can be made about the compound? a. It has the formula XZ2 b.