Question | Answer |
Matter | Chemistry is the study of matter which is anything that occupies space and has weight |
Element | Is matter that is composed of atoms that have the same number of positive charges in their nuclei. |
4 elements that make up 96% of the human body | Oxygen (O), Carbon (C), Hydrogen (H), Nitrogen (N) |
Subatomic particles in the nucleus of the atom | protons and neutrons |
Subatomic particles that orbit the atom's nucleus | Electrons |
Each atom is neutrally charged because | the number of protons equals the number of electrons |
All neutrons are alike, all protons are alike and all electrons are alike - so what makes atoms different | the number of protons and electrons in each atom. Hydrogen is the simplest with 1 proton and 1 electron; Helium has 2 of each |
Atomic Number | the number of protons in the nucleus |
Atomic Mass | Adding the number of protons and neutrons in the nucleus - |
Isotope | different form of same atom. Has same atomic number (protons in nucleus), but different atomic mass - neutrons are added |
Radioisotopes | Isotopes are unstable and give off energy that can damage cells. Used to destroy cancer cells and for diagnostic |
3 Chemical Bonds | Ionic; Covalent; Hydrogen |
Ionic Bond | caused by a transfer of electrons between atoms. sodium has 11 protons and 11 electrons, but single electron in outer shell make it unstable so donates it to chlorine who needs an extra electron forming ionic bond NaCl |
Covalent Bond | sharing electrons by outer shells of atoms. Oxygen needs 2 and Hydrogen needs 1-2 hydrogen share 1 electron each with an oxygen atom = H2O. strong bond, no dissolve in water; carbon always forms covalent bonds with O, N, H-in body; makes protein, enzyme, |
Hydrogen Bond | weak positive charge of water molecule on hydrogen end, and negative around oxygen end cause polarity. makes water molecules stick together, it is a polar molecule |
Ions | Atoms that carry an electrical charge. if an electron is lost or gained, the electrical charge changes from neutral to + or -. If an electron (-) is lost ion is +. |
Cation | Ion with positive charge |
Anion | Ion with negative charge |
Electrolyte | substance that forms ions when it is dissolved in water. capable of conducting electrical current; ECG and EEG |
Ionization | when electrolytes break apart in solution they dissociate; salt breaks into Na+ and Cl-. because the result is 2 ions, process is ionization. Only electrolytes ionize |
Water is essential for... | universal solvent; temperature regulator; lubricant; chemical reactions (breakdown carbs) protective (surrounds brain) |
Oxygen is essential for.. | used by cells to liberate energy from the food we eat |
Catalysts | speed up chemical reaction |
Enzymes | proteins that act as catalysts |
Acid | an electrolyte that disassociates into a hydrogen ion (H+) and an anion. strong acids disassociate completely into H+ (stomach acid) vinegar remains mostly unassociated |
Base | substances that combine with H+ |
pH | unit of measurement that indicates how many H+ are in the solution. at midpoint of 7 solution is neutral; less than 7 has more H+ and is acid; more than 7 has less H+ and is base or alkaline |
pH of less than 7 indicates a... | is acid - contains more H+ |
pH of more than 7 indicates a... | base - contains less H+ |
pH of -0- has _____ H+ and is an _____ | more ; acid |
Normal blood pH is _____ to _____ | 7.35-7.45 - slightly alkaline |
Acidosis | blood pH is less than 7.35 |
Alkalosis | blood pH is more than 7.45 |
Body regulates pH with... | kidneys; lungs and buffers |
ATP | adenosine triphosphate - energy transfer molecule; food is transferred to ATP that can be used by cells for energy |