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

21 Which mathematical expression represents the heat of reaction for a chemical reaction? (1) (the heat of fusion) - (the heat of vaporization) (2) (the heat of vaporization) - (the heat of fusion) (3) (the potential energy of the products) - (the

What must happen in a chemical reaction? A. Energy is created B. Energy is transferred. C. Atoms are destroyed. D. Energy is destroyed

Which quantities must be conserved in all chemical reactions? 1) mass, charge, density 2) mass, charge, energy 3) charge, volume, density 4) charge, volume, energy

What 2 instruments are commonly used to measure air pressure?

Sophie sees a truck loaded with animals while traveling from Texas to Louisiana. The animals were cramped unhygienic cages. Which veterinary personnel should she contact immediately? A) Shelter medicine veterinarian. B) Consulting veterinarian.

Which is a non renewable resource that is used to generate electrical energy

How many grams of sulfur (S8S8) must be dissolved in 100.0 g naphthalene (C10H8C10H8) to make a 0.11 mm solution

Mason compare the properties of two compounds magnesium oxide is an ionic compound and hydrogen peroxide is not an ionic compound there for both compounds most likely

Cisplatin is synthesized as follows: K2PtCl4 (aq) + 2NH3 (aq)  Pt (NH3) 2Cl2 (s) + 2KCl (aq) What mass of cisplatin can be made from 100. g of K2PtCl4 and sufficient NH3? What mass of KCl is also produced?

What is the total number of protons in the nucleus of an atom of potassium-42? (1) 15 (3) 39 (2) 19 (4) 42