Term
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Definition
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Term
| 2. Difference between precision and accuracy? |
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Definition
| Precision is how repeatable a measurement is while accuracy is how close the measurement is to it's true value |
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Term
| 3. Explain three types of ways to separate substances by physical means. |
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Definition
1) Distillation: evaporating a liquid and condensing it's vapor
2) Filtration: using filter paper to separate a solid and a liquid by using the filter paper to catch the solid
3) Chromatography: various components of a substance are put through the chromatography process when they are flushed through a system at different rates over absorptive materials which provide the means of separation |
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Term
| 4. What is atomic number? |
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Definition
| The number of protons (which also equals the number of electrons if the atom is neutral) |
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Term
| 6. Compare the reactivity of metals and nonmetals; and the reactivity of alkali metals, alkaline earth metals, halogens, and noble gases. |
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Definition
Metals are cations, they lose electrons. Nonmetals are anions, they gain electrons.
Alkali metals: very reactive
Alkaline earth metals: not as reactive
Halogens: very reactive
Noble gases: unreactive |
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Term
| 7. Explain the Law of Definite Proportions and the Law of Multiple Proportions. |
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Definition
Law of Definite Proportion (Proust): compounds have a constant composition
Law of Multiple Proportions: when two elements form a series of compounds, the ratios of the masses of the second elements that combine with the first elements can always be reduced to a small whole number |
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Term
| 8. How do you find protons, neutrons, electrons and charge of a neutral atom and an atom with a charge? |
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Definition
| The atomic number it the number of protons; a neutral atom has the same number of electrons as protons. The number of neutrons can be found by subtracting the number of protons from the mass number (the atomic weight). |
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Term
| 9. What is electronegativity and what is the most electronegative element? |
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Definition
| An atom's ability to attract another electron. The most electronegative atom is florine. On the periodic table, as you go down, electronegativity decreases because you are adding energy levels so electrons are further away from the nucleus and better shielded from the nuclear charge and thus not as attracted to the nucleus. As you go across the periodic table electronegativity increases because nuclear charge increases, so the attraction that the atom has for electrons increases as well. |
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Term
| 11. What is the Pauli Exclusion Principle and Hund's Rules? |
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Definition
| Given an atom, no to electrons can have the same set of quantum numbers (must have opposite spins); the lowest energy configuration for an atom is the one having the maximum number of unpaired electrons. |
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Term
| 13. Describe the ionic radius of a cation and an anion compared to a neutral atom. |
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Definition
| A cation has more electrons than it's neutral atom so it's smaller and a anion has less electrons than it's neutral atom so it's larger |
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Term
| 15. What is ionization energy? Explain it in regard to the periodic table. |
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Definition
| The energy required to remove an electron; as you go down the periodic table ionization energy decreases because there are more energy levels so the valence electrons are further from the nucleus and are not as strongly attracted to the nucleus; and as you go across the periodic table, ionization energy increases because the attraction between the nucleus and the electrons (nuclear charge) increases and it requires more energy to remove the outermost electron. |
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Term
| 16. What is wavelength and frequency and how can you find it? What equation is needed to find the energy per photon? |
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Definition
the distance between two peaks and the number of waves per second that pass a given point in space. They can be calculated by using the equation: wavelength x frequency = speed of light (3.00x10*8 m/s);
E(photon)= n(integer)x h(Planck's constant: 6.63x10*-34 J/s)x v(frequency) |
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Term
| 18/19. What is molar mass, Avogrado's Number, and molar volume? |
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Definition
| the mass in grams of one mole of a compound; 6.02x10*23 units, particles, atoms, molecules, formula units in one mole; 22.4 L is one mole of gas at STP |
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Term
| 22. What is molarity and dilution? |
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Definition
| The amount of moles of a substance per liter of solvent and when you add more solvent to a known solution (the moles of the solute stay the same thus M1V1=M2V2) |
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Term
| 24/25. What is oxidation and reduction? |
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Definition
| Oxidation is the loss of electron; the substance that gets oxidized is the reducing agent. Reduction is when electrons are gained; what gets reduced is the oxidizing agent. |
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Term
| 26. What are net ionic equations? |
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Definition
| Chemical equations that only show the ions that react (not the spectator ions). |
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Term
| 28. What is the limiting and the excess reagent? |
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Definition
| The reactant that determines how much product is made, it gets used up first; and the excess reagent is the reactant that is left over after the reaction occurs. |
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Term
| 29. How do you find the pressure of a gas collected over water? |
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Definition
| Subtract the pressure of the water from the total pressure. |
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Term
| 30. What is effusion? How do you calculate effusion rate? |
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Definition
| The passage of gas through a small hole into a vacuum; effusion rate measures how fast this happens and is calculated by using the equation: r1 / r2 = √(M2 / M1) |
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Term
| 36. What is the equation for molar enthalpy, specific heat, and heat? |
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Definition
| molar enthalpy: heat of reaction/ mole; heat capacity (C): heat absorbed/ temperature change; heat: mass x temperature change x specific heat capacity. |
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Term
| 49. Identify and define paramagnetic and diamagnetic. |
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Definition
| atoms have unpaired electrons which gives them a magnetic field; atoms only have paired electrons so they do not have a magnetic field. |
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Term
| 54. What are hydrogen bonds? |
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Definition
| bonds where a hydrogen atom is bonded to a highly electronegative atom. |
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