Which examples represent chemical changes? Check all that apply.

burning wood

souring milk

melting copper to join two copper pipes together

browning of a cut apple

cutting a potato into small pieces

How many moles are in 23.4 g

Two clear liquids are combined. A green solid forms. color change absorption of heat formation of precipitate formation of gas

The reaction A 2B C 2D is run 3 times. In the second run, the initial concentration of A is double that in the first run, and the initial rate of the reaction is double that of the first run.

Based on the periodic table, which of the following groups of elements should have very similar chemical properties? A. potassium (K), aluminum (Al), neon (Ne) B. carbon (C), iodine (I), hydrogen (H) C. lithium (Li), sodium (Na), potassium (K) D.

How does a thermos filled with ice and tea keep the tea cold

In a solution such as salt water, the component that is dissolved is called the O solute O solvent O suspension O colloid

Which is the balanced chemical equation showing hydrogen peroxide (h2o2) decomposing into hydrogen (h2) and oxygen (o2) ? 1. h2 + o2 → h2o2 2. 2 h2o2 → 2 h2 + o2 3. h2o2 → h2 + o2 4. 2 h2 + o2 → 2 h2o2?

Assuming constant pressure, rank these reactions from most energy released by the system to most energy absorbed by the system, based on the following descriptions: A. Surroundings get colder and the system decreases in volume. B.

Zircon is a mineral with the empirical formula ZrSiO4. If all the zirconium is 90Zr, all the silicon is 28Si, and all the oxygen is 16O, what mass of oxygen is present in 10. g of zircon?

Which property below is not a general property of metals: A. Ductile C. Malleable B. Poor conductor of heat D. High luster