A chemistry student named Hector had a cup of hydrogen peroxide, H2O2, that weighed 40.27 g. He walked away and forgot about it so when he returned he reweighed it just to be sure. Shockingly, he found it only weighed 33.16 g!?! Hector knows his chemistry and knows that matter can’t be created or destroyed. Look closely at the equation - what could explain the reduction in mass?

Scientists often have to deal with numbers that are either very large or very small. for example, the radius of the sun is approximately 696,000 kilometers, while bacterial cells are as small as 1.9 × 10-4 millimeters. express each number in an alternate form.

The graph shows one consequence of urban sprawl. how did urban sprawl contribute to the change in biodiversity

An unknown substance is a white solid at room temperature and has a melting point of 78 °c. which of the following substances is most likely to be the identity of the unknown sample? a. naphthalene, a molecular solid with the formula c10h8 b. silica, a network solid held together by covalent bonds with the formula sio2 c. calcium chloride, an ionic compound with the formula cacl2 d. water, an molecular compound with the formula h2o