UV absorption

TLS Online TPP Program

#Id: 7765

#Section 2: General Biology

An endothermic reaction (AH positive, heat absorbed) results when the bonds in the products are weaker than those in the reactants

TLS Online TPP Program

#Id: 7763

#Section 2: General Biology

Breaking a bond always require energy to be added to the molecule. Correspondingly, making a bond always releases energy.

TLS Online TPP Program

#Id: 7761

#Section 2: General Biology

A covalent bond is a chemical bond that occurs when two or more atoms share electrons. The sharing of electrons helps complete the outer shell, or valence shell, of both atoms. The sharing of electrons creates a stable balance of attractive and repulsive forces between atoms.

TLS Online TPP Program

#Id: 7760

#Section 2: General Biology

Sulfur normally exists as an eight-atom molecule, S8, while phosphorus exists as a four-atom molecule, P4

TLS Online TPP Program

#Id: 7759

#Section 2: General Biology

Some elements exist naturally as molecules. For example, hydrogen and oxygen exist as two-atom molecules.

TLS Online TPP Program

#Id: 7758

#Section 2: General Biology

A molecule is the smallest part of a substance that has the physical and chemical properties of that substance. In some respects, a molecule is similar to an atom. A molecule, however, is composed of more than one atom.