Nature of Science/Extra things I ran out of room for... :)
Describe the steps of the scientific method.
Develop question, create hypothesis, test hypothesis/conduct experiment, collect data, draw a conclusion.
These are the two main classifications of matter.
What are pure substances and mixtures?
Describe the structure of an atom in terms of subatomic particles and their charges.
Nucleus contains protons (+) and neutrons (0). Electron cloud contains electrons (-).
These are the four items found within a square on the periodic table.
Chemical name, chemical symbol, atomic number, atomic mass.
These are the four types of chemical reactions.
What are synthesis, decomposition, single-replacement, and double-replacement?
Calculate the density of an object whose mass is 50 g and whose volume is 1.25 mL. *Remember your units!
40 g/mL
Melting, Freezing, Evaporation, Condensation, Sublimation, Deposition
How is the mass number calculated?
Protons + neutrons
Group: vertical columns, similar chemical properties. Period: horizontal rows, same energy levels
Describe a covalent bond (what's it between? what happens with electrons?) and give an example of one.
Covalent bonds are where elements share electrons. It occurs between two non-metals. (CO2, H2O, Cl2).
Name and define the three different variables found in an experiment
Independent variable = changed by scientist, dependent variable = measured/observed, control/constant = remains the same.
Describe the two types of mixtures.
Heterogeneous - different throughout... can see different parts. Homogeneous - same throughout.
Name the experiment and discovery that J. J. Thomson is famous for.
Cathode ray tube, discovered electrons.
Describe the valence electron trend and how it is related to oxidation numbers on the periodic table.
Valence electrons increase as you read left to right on a periodic table. Valence electrons tell you how many e-'s the atom will gain/lose in a bond. This affects an atom's oxidation number, which is what charge the atom will become when it gains/loses electrons in chemical bonding.
Describe an ionic bond (what is it between? what happens with electrons?), give an example, and explain how to name it.
Ionic bonds occur between a metal and a nonmetal where they completely transfer electrons. Ex: NaCl, MgO, etc. Name: keep metal, change non-metal to -ide
Classify the mixtures into three types. Discuss their particle size, if it scatters light, and if the particles settle. Give an example of each.
Name 4 signs that a chemical reaction has occurred.
Ex: color change, odor change, solid produced in a liquid, formation of gas, heat produced, light emitted, a new substance has formed.
Name the experiment and the discovery that Ernest Rutherford is famous for.
Metals on the left of the staircase, metalloids on the staircase, nonmetals to the right of the staircase.
What is the correct way to write:
1. sodium phosphate
2. aluminum chloride
3. dinitrogen pentoxide
Na3PO4, AlCl3, N2O5
Describe the trend of ionization energy AND electronegativity as you move across the PT and down a group. Name the most electronegative element, as well.
Both increases across the PT and decreases down a group. Fluorine is the most electronegative.
Unsaturated: solvent is greater than solute.
Saturated: solvent and solute are equal.
Supersaturated: solute is greater than solvent. solvent cannot dissolve more solute & will settle at the bottom.
Describe an isotope and tell me how to find the most abundant isotope from the periodic table.
Isotope = same number of protons, different number of neutrons. Most abundant = look at atomic mass and round to the nearest whole #.
Name all the groups on the periodic table!
Alkali metals, alkaline earth metals, transition metals, boron group, carbon group, nitrogen group, oxygen group, halogens, noble gases. (extra: rare earth metals/lanthanides & actinides)
Balance this equation:
C2H6 + O2 --> CO2 + H2O
2C2H6 + 7O2 --> 4CO2 + 6H2O