What is the main reason scientists perform experiments

a) to summarize experimental information

b) to collect scientific data

c) to find answers to their questions

d) to play with equipment in the lab

Which of the following items represents a chemical change? burning melting evaporation freezing

A new penny has a mass of 2.49 g and a volume of 0.349 cm3. Is the penny made of pure copper?

How has radiometric dating made the construction and interpretation of the stratigraphic record more reliable

If an ionic compound were composed of a4 + and b-, which unit cell structure would give a neutral compound?

Name these Ionic Compounds a. LiCl b. NaCl c. KBr

Organize the items listed into the proper sequence of events for gas exchange. a: O2 is transported to cells by circulatory system. b: O2 is drawn into the lungs during inhalation. c: Cells use O2 and generate CO2. d: CO2 is exhaled.

Research about the reaction of baking soda and vinegar

What mass (in mg) does 2.63 moles of nickel have? 3.56 * 105 mg 1.54 * 105 mg 2.23 * 104 mg 129 mg?

Given the propane molecule C3H8 (g) ! a) What is the balanced equation for the combustion of propane in O2? (20 pts.) b) What is the standard enthalpy change ΔH0 for the reaction at 25°C? (20 pts.

Which of the following happens during a chemical change? Check all of the boxes that apply. One atom or more changes into atoms of another element. New substances with different properties are formed. Solids, liquids, or gases may form.