Is burning a leaf a chemical change or physical change

Which of the following is nicknamed the "powerhouse" of the cell?

High-level radioactive waste requires deep burial because it is explosive. TRUE FALSE

Osmosis is defined as the movement of A. Molecules from high concentration to a low concentration B. Water molecules from a high concentration to a low concentration through a selectively permeable membrane C.

If State A is heated, which of the other two states would it more closely resemble? Explain.

Calculate ∆h0 for the following reaction. br2 ( g. → br2 (l) ∆hf0 br2 ( g. = 30.91 kj/mol; ∆hf0 br2 (l) = 0 kj/mol)

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.

Are protons positive and neutrons neutral

Why might it be useful to determine the elements that a planet or moon is made up of?

Which of these is an example of a solution A Sand stirred in water B Sugar stirred in tea C A glass of water with ice in it D Oil and vinegar in a salad dressing jar