TX PACT 4-8 CORE (790)| 197 QUESTIONS| WITH COMPLETE SOLUTIONS

How many SFs in 0.? Correct Answer: 8 SFs: Addition and Subtraction Rules Correct Answer: answer has the same # decimal places as numeral w/the smallest # of decimal places. EX: 1063.02 + 12.5 = 1075.5 SFs: Multiplication/Division Rules Correct Answer: answer has the same # of SFs as numeral with smallest # of SFs. EX: 1063.02 x 12.5 = 13287.75 => 1.33 x 10^4 Define: Hypothesis, Theory, and Scientific Law Correct Answer: Hypothesis: testable prediction based on observations (educated guess) Theory: proposed explanation, based on evidence, that may or may not be testable. (educated explanation on why something happens) Scientific Law: proven and documented description of observations surrounding phenomena (states what will happen not why) *theories do not become laws independent variable Correct Answer: The experimental factor that is manipulated by the scientist; the variable whose effect is being studied. (usually on x-axis) dependent variable Correct Answer: The measurable factor; the variable that may change in response to (or depend on) manipulations of the independent variable. Precision Correct Answer: a measure of how close a series of measurements are to one another Accuracy Correct Answer: how close a measurement is to the true value Negative feedback Correct Answer: A type of regulation that responds to a change in conditions by initiating responses that will counteract the change or correct the system back to original state. Maintains a steady state (homeostasis). EX: body temperature Positive feedback Correct Answer: A type of regulation that responds to a change in conditions by initiating responses that will amplify the change. Takes organism away from a steady state. EX: Global warming or contractions Matter Correct Answer: Anything that has mass and takes up space (made up of atoms) Ground state of atoms Correct Answer: lowest energy, most stable electron configuration