Which of the following represents a chemical change?

A. Bending a wire

B. Freezing of water

C. Fireworks exploding

D. Melting of a wax candle

Which of these gases is most responsible for the greenhouse effect on earth? oxygen (o2) nitrogen (n2) carbon dioxide (co2) ozone (o3) ammonia (nh3) ?

Identify items in your life that are made of each type of element: metal, nonmetal, and metalloid. For each item, explain why the properties of that type of element are necessary for the function of that item

What kind of element has the greatest tendency to attract electrons? why?

The science that deals with the study of the stuff that makes up the universe is chemistry?

The molecular mass of the compound is 132 amu. What is the molecular formula?

Describe three characteristics that trees used to build treehouses should have. why are these characteristics essential

Select the correct value for the indicated bond angle in each of the following compounds: O-S-O angle of SO2 F-B-F angle of BF3 Cl-S-Cl angle of SCI2 O-C-O angle of CO2 F-P-F angle of PF3 H-C-H angle of CH4

What is the shape of a molecule with a triple bond?

4FeS2 + 11O2 > 2Fe2O3 + 8SO2 Given 75.0 grams of iron (IV) sulfide, how many grams of sulfur dioxide are produced?

Cytotoxic t cells can attack target cells with which chemical weapons?