MTTC Integrated Science Secondary (94) Questions and Answers 100% Accurate.

What are the 5 steps in the Scientific Method? - ANSWER-1. Identify a problem or pose a question based on an observation. 2. Formulate a hypotheses. 3. Conduct experiments or tests the hypotheses. 4. Observe and record the results. 5. Draw a conclusion (was the hypothesis correct?). * peer review is also important. Metric Unit deca (da): - ANSWER-x 10^1 Metric Unit hecto (h): - ANSWER-x 10^2 Metric Unit kilo (k): - ANSWER-x 10^3 Metric Unit mega (M): - ANSWER-x 10^6 Metric Unit giga (G): - ANSWER-x 10^9 Metric Unit deci (d): - ANSWER-x 10^-1 Metric Unit centi (c): - ANSWER-x 10^-2 Metric Unit milli (m): - ANSWER-x 10^-3 Metric Unit micro (µ): - ANSWER-x 10^-6 Metric Unit nano (n): - ANSWER-x 10^-9 Metric Unit pico (p) - ANSWER-x 10^-12 What is an Independent Variable and what axis is it plotted on in a graph? - ANSWER-*The variable that acts as a control or does not change during an experiment. *x axis What is an Dependent Variable and what axis is it plotted on in a graph? - ANSWER-*The variable that changes in response to the independent variable. This change is measured to determine the effect of the independent variable on the dependent variable. *y axis What are random experimental errors? - ANSWER-Errors that are not consistent across the data set. * can result in collected data that does not seem to fit and may be wildly different from the rest of the data, or they may result in data that is indistinguishable from the rest. * may be the result of outside factors that are not considered variables *referred to as noise What are systematic experimental errors? - ANSWER-An error that will show up consistently across a sample or data set. *may be the result of a flaw in the experiment design or instrumentation *affects the average *known as a bias Chemistry lab fire hazards - ANSWER-Volatile solvents: ether, acetone, benzene *store in open beaker or Erlenmeyer flask *use extreme caution around sparks * heat in fume hood with a steam bath (not on a hot plate) Chemistry lab chemical burns - ANSWER-Mineral acids and alkalis are corrosive to the skin and eyes *acid halides and phenols are corrosive and often toxic Chemistry lab toxic chemicals that can be absorbed through the skin - ANSWER-dimethyl sulfoxide (DMSO) nitrobenzene Chemistry lab toxic fume inhalation - ANSWER-acetyl chloride- severely irritate membranes in the eyes, nose, throat, and lungs benzyl chloride- eye irritation and tears Simple microscope - ANSWER-a microscope that contains only one lens Compound microscope - ANSWER-Microscope that contains two or more lenses to increase total magnification (usually 3 lenses) *multiply each magnification to obtain total magnification Accuracy of balances - ANSWER-Most accurate- Electronic triple- beam Least- Spring balance Chromotography - ANSWER-Is the separation of a mobile phase carrying a mixture that moves in contact with a selectively absorbent stationary phase. Analyte - ANSWER-The substance or chemical being analyzed or detected in a specimen reagent - ANSWER-a chemical agent for use in chemical reactions centrifuge - ANSWER-an apparatus that uses centrifugal force to separate particles from a suspension Heterogeneous mixture - ANSWER-A mixture in which different materials can be distinguished easily precipitate - ANSWER-A solid that forms and settles out of a liquid mixture supernatant - ANSWER-liquid above the precipitate that remains after centrifugation that can be removed from the precipitate with a pipet- also called centrifugate Spectrophotometry - ANSWER-An analytical method for identifying a substance by its selective absorption of different wavelengths of light. Electrophoresis - ANSWER-A technique for separating macromolecules (proteins, RNA, DNA) on a gel using an electric field. Calorimetry - ANSWER-The measurement of heat flow (into or out of a system) as the result of a chemical reaction or physical process. Titration - ANSWER-a measured amount of a solution of unknown concentration is added to a known volume of a second solution until the reaction between them is just complete Charles Robert Darwin - ANSWER-Author of "On the Origin of Species" and founder of modern evolution