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Chem Asssessment 1
Term | Definition |
---|---|
Diffusion | Random movement of particles to fill available space and spread evenly. (Using Brownian motion, gas travels from high concentration to low concentration.) |
Factors Affecting Diffusion | Molar Mass of Substance: Larger = Slower Temperature: Hot = Fast |
Diffusion of Hydrogen Chloride and Ammonia gas through air to form Ammonium Chloride. | Two cottons, one soaked in ammonia solution, one soaked in concentrated hydrochloric acid, are placed on opposite ends of a tube sealed by corks. The gases meet closer to the HCl because ammonia molecules travel faster due to lower molar mass. |
Subatomic Particles, their mass, and their charges. | Proton: +1, 1 Electron: -1, 0 Neutron: 0, 1 |
Diffusion in Liquids | Slower than diffusion in gas, but still possible because particles move around slowly. |
Brownian Motion | Random motion of Particles. |
Latin names of: Antimony, Copper, Iron, Lead, Mercury, Potassium, Sodium, Tin, and Tungsten. | Stibium, Cuprum, Ferum, Plumbum, Hydragyrum, Kalium, Natrium, Starnum, Wolfram |
Atoms | Fundamental building blocks of matter. Retains its identity during chemical reactions. Smallest unit of matter. |
Elements | Simplest pure substance. |
Molecules | Two or more atoms chemically combined in a fixed proportion. |
Compounds | Multiple Molecules |
Nucleus | Contains mass of atom (Protons/Neutrons) |
Electron cloud | Contains most of the space in the atom + Electron shells. |
Isotopes | Various atoms of the same element with different numbers of neutrons. |
Isotopes of Hydrogen | Regular Hydrogen (0 neutrons), Deuterium (1 neutron), tritium (2 neutrons) |
Radioisotopes | Decay randomly, Half-life is known |
Half-life | How long it takes for half the radioisotopes in a sample to decay. |
Carbon dating | Uses half-life of Carbon-14 |
Relative atomic mass | A<sub>r</sub> Average mass of atoms. (%*mass number) + (%*mass number) etc. |
Ammonium | NH4+ |
Hydride | H- |
Oxide | O-2 |
Fluoride | F- |
Sulfide | S-2 |
Chloride | Cl- |
Nitride | N-3 |
Bromide | Br- |
Iodide | I- |
Phosphate | PO4-3 |
Sulphate | SO4-2 |
Nitrate | NO3- |
Carbonate | CO3-2 |
Hydroxide | OH- |
Chlorine Isotopes | Chlorine-35 (75%) Chlorine-37 (25%) |
Carbon Isotopes | Carbon-12 (98.9%) Carbon-13 (1%) Carbon-14 (less than 0.01%) |
Diatomic Atoms | Hydrogen, Iodine, Oxygen, Fluorine, Chlorine, Bromine, Nitrogen |
Group I (Alkali Metals) | React with water to form alkalis Li, Na, K, Rb, Cs, Fr Radioactive element: Francium Solids Soft metals Good conductor of heat and current Low density (float on water) Low MP, BP Form ionic compounds |
Alkali Metals + Water | Alkali Metal + Water -> Alkali Metal Hydroxide + Hydrogen Lithium: Fizz around the floating metal Sodium: Shoots on the surface of the water Potassium: Melts and bursts into flame Rubidium: Sparks Cesium: Violent explosion |
Alkali Metals + Halogens | Alkali Metal + Halogen -> Alkali Metal Salt(Halogen) White solid Dissolves completely in water (colorless solution) |
Alkali Metals + Oxygen | Alkali Metal + Oxygen -> Alkali Metal Oxide + Colored Flame |
Down the group (alkali metals): | Softness increases Density increases MP/BP decrease Reactivity increases (valence electrons get farther from the nucleus and are easier to lose) |
Flame color of Alkali metals | Lithium: Red-orange Sodium: Golden yellow Potassium: Lilac |
Alkaline Earth Metals + down the group | Be, Mg, Ca, Sr, Ba Softness increases MP, BP decreases Reactivity increases |
Alkaline Earth Metals vs Alkali Metals | Group II are less reactive (2 valence electrons vs 1) Group I are softer Group II MP/BP are higher Group II higher density |