2. What happens when an electron returns to

its ground state from its excited state?

Which statement correctly describes two forms of oxygen, O2 and O3? (1) They have identical molecular structures and identical properties. (2) They have identical molecular structures and different properties.

Which process represents a chemical change? (1) melting of ice (2) corrosion of copper (3) evaporation of water (4) crystallization of sugar

7. Which motion causes night and day on Earth? * O A the Sun's motion around its axis B Earth's motion around its axis O C Earth's motion around the Sun O D the Moon's motion around Earth

Which statements describe an ideal gas

The density of E85 fuel is 0.801 g/mL. What is the mass of 1.00 gallon of the fuel? (1 gal. = 3.785 L)

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.