Exam 1 Flashcards
What’s an Element?
The substances that cannot be broken down into simpler substances by chemical reactions.
What are the main elements of the body? (Remember CHNOPS)
Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, and Sulfur.
What are atoms?
Basic building block of chemistry. Contain protons, neutrons, and electrons.
Bonds?
Sharing of electrons
Bond Energy
Energy needed to break a bond
Covalent Bond
When two electrons are shared so the outer valence shells become filled. More than one bond can occur.
Ionic Bond
When electrons are donated from one atom to another, or an electronegative atom steals an electron from another atom to fill its valence shell.
Hydrogen Bonds
When polarized molecules like H2O have a + charge and - charge that help in holding the molecules together. Weak bond. Think magnets.
Water
Is polar (dipole), Oxygen element pulls in hydrogen elements through a covalent bond and the O end becomes negatively charged and the H ends remain positive.
Solvent
Good at dissolving other substances
Solute
Good at being dissolved (salt)
What does water help do?
Essential to life and helps regulate earth’s temperature.
What is pH?
Measure of free hydrogen ion concentration.
pH what makes it basic?
When water has reduced number of protons (hydrogen ions)
pH what is acidic?
When water has an excess amount of protons (hydrogen ions).
