Methane, or ch4, is an example of a molecule whose atoms are held together by which of the following?
a. hydrogen bonds
b. covalent bonds
c. metallic bonds
d. ionic bonds

Embryos of different species look very similar, which shows that the organisms share a ancestor.

When 225mg of anthracene, c14h10(s), was burned in a bomb calorimeter the temperature rose by 1.75k. calculate the calorimeter constant. by how much will the temperature rise when 125mg of phenol, c6h5oh(s), is burned in the calorimeter under the same conditions? (δch< (c14h10,s)=–7061 kj mol−1.)

Light waves can move through , but they travel fastest when they move through a(n) .