Which of the following is an example of a chemical change?

a. water evaporating from a puddle on a hot day

b. burning a piece of toast

c. cracking open an egg and removing the yolk

d. steam condensing on the bathroom mirror

Chemical energy is energy that is a. added to a reaction in the form of heat. c. caused by the movement of electricity. b. stored in the bonds between atoms of a molecule d. released only when oxygen is present.

64.0 grams of Sulfur Dioxide absorbed 5.00 kJ of heat and immediately evaporated. With this information, calculate its molar enthalpy of vaporization in units kJ/mol.

What does living organisms consist mostly of

A chemist adds 405.0mL of a 0.79M sodium carbonate solution to a reaction flask. Calculate the millimoles of sodium carbonate the chemist has added to the flask. Be sure your answer has the correct number of significant digits.

What is electron configuration of sulfer?

A mixture of two compounds, a and b, was separated by extraction. after the compounds were dried, their masses were found to be: 105 mg of compound a and 91 mg of compound b. both compounds were recrystallized and weighed again.

What are the five types of chemical reactions?

Which chemical reaction do plants use to take carbon dioxide out of the air

What are the primary elements of the earths layres?

How long does it usually take fir a rock to undergo a stage within the rock cycle