Which is a chemical property of oxygen. a. it expands when heated b. it combines to form o2 molecules c. it is a gas at room temperature d. it reacts with iron to form rust

The excretory system,need answers for all: )

Which statement justifies that hydrogen peroxide (h2o2) is a polar molecule? the o – h bond is nonpolar and the molecule is asymmetric. the o – h bond is nonpolar and the molecule is symmetric. the o – h bond is polar and the molecule is asymmetric. the o – h bond is polar and the molecule is symmetric.

Scientists often 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 of these numbers in an alternate form.