CHAPTER2
CHAPTER #2
Acid | a substance that increases the hydrogen ion (H⁺) concentration in a solution x<6 | Beer, orange juice, wine, sodas |
Atom | the smallest unit of an element | H/1, C/6, N/7/, O/7 |
Atomic mass | primarily determined by the number of protons and neutrons | H = 1 + 1 = 2 |
Atomic number | number of protons in the nucleus | H = 1 |
Base | substance that reduces the hydrogen ion concentration in a solution, often by producing hydroxide ions (OH⁻) x>8 | Soap, baking powder, bleach, and blood (a little bit) |
Chemical reaction | process that leads to the transformation of one set of chemical substances into another | Burning fossil fuel, digestion |
Cohesion | attraction between molecules of the same substance | often seen in water molecules |
Covalent bond | Chemical bonds are formed when two atoms share one or more pairs of electrons. | Nonpolar= Same & C O gas Polar = stronger pull of electrons in a water molecule |
Double bond | A chemical bond where two pairs of electrons are shared between atoms | Carbon dioxide |
Electron | a subatomic particle with a negative charge | Shell = inner 2 Outer = 8 |
Element | substance that cannot be broken down into simpler substances | Hydrogen, Helium, Oxygen, Carbon |
Hydrogen bond | weak bond between two molecules resulting from an electrostatic attraction between a proton in one molecule and an electronegative atom in another | Body of water, Alcohol |
Ion | atom or molecule with a net electric charge due to the loss or gain of one or more electrons | Sodium, calcium, potassium |
Ionic bond | chemical bond formed between two ions with opposite charges | Table salt (NaCl) |
Isotope | Atoms of the same element with the same number of protons but different numbers of neutrons | Carbon 12; Carbon 13; Carbon 14 |
Molecule | group of atoms bonded together; the smallest unit of a chemical compound | H2O, C6H12O6, NaCl |
Neutron | subatomic particle found in the nucleus | No charge |
Nucleus | the central part of an atom; protons + neutrons | Middle of the atom & Atomic mass |
Periodic table | table of chemical elements arranged by atomic number |
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pH | measure of how acidic or basic a solution is; scale of 0 to 14 |
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Polar molecule | molecule with an uneven distribution of charge, resulting in positive and negative poles | Water, sulfer dioxide |
Proton | Positive subatomic particle | In the nucleus |
Radioactive | an unstable atom that decays over time, emitting radiation | In the # of neutrons |
Hydrophilic | affinity for water | Polar = Glucose, starch |
Hydrophobic | Repelling water | Nonpolar = Oil, fats |
Solvent | liquid that dissolves a solute | water |
Solute | substance that is dissolved in a solvent | sugar |
Solution | mixture of two or more substances | Sugar water |
Surface tension | cohesive force at the surface of a liquid that makes it behave as if a thin elastic sheet covered it |
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