Science (125 Questions) Flashcards
(125 cards)
1
Q
What is the scientific method?
A
A systematic approach to investigate natural phenomena
2
Q
What is a controlled variable?
A
A factor kept constant in an experiment
3
Q
What is the difference between accuracy and precision?
A
Accuracy is how close to the true value; precision is how close repeated measurements are
4
Q
What is a theory in science?
A
A well-substantiated explanation supported by evidence
5
Q
What is the difference between quantitative and qualitative data?
A
Quantitative involves numbers; qualitative involves descriptions
6
Q
What is peer review?
A
Evaluation of research by experts before publication
7
Q
What is replication in science?
A
Repeating experiments to verify results
8
Q
What is the difference between mass and weight?
A
Mass is amount of matter; weight is gravitational force
9
Q
What is density?
A
Mass per unit volume (D = m/V)
10
Q
What is the unit for force in the metric system?
A
Newton (N)
11
Q
What is momentum?
A
Mass times velocity (p = mv)
12
Q
What is impulse?
A
Change in momentum or force times time
13
Q
What is centripetal force?
A
Force directed toward the center of circular motion
14
Q
What is torque?
A
Rotational force (force times distance from pivot)
15
Q
What is pressure?
A
Force per unit area (P = F/A)
16
Q
What is Archimedes’ principle?
A
Buoyant force equals weight of displaced fluid
17
Q
What is Pascal’s principle?
A
Pressure applied to confined fluid is transmitted equally
18
Q
What is Bernoulli’s principle?
A
As fluid speed increases, pressure decreases
19
Q
What is specific heat?
A
Amount of heat needed to raise 1 gram of substance 1°C
20
Q
What is latent heat?
A
Energy required for phase change without temperature change
21
Q
What is thermal expansion?
A
Increase in size due to temperature increase
22
Q
What is electromagnetic radiation?
A
Energy transmitted as waves or particles
23
Q
What is the electromagnetic spectrum?
A
Range of electromagnetic radiation from radio waves to gamma rays
24
Q
What is wavelength?
A
Distance between two consecutive peaks of a wave
25
What is the relationship between wavelength and frequency?
They are inversely proportional (c = λf)
26
What is Doppler effect?
Change in frequency due to relative motion
27
What is interference in waves?
When two waves combine to create a new wave pattern
28
What is constructive interference?
When waves combine to increase amplitude
29
What is destructive interference?
When waves combine to decrease amplitude
30
What is diffraction?
Bending of waves around obstacles
31
What is polarization?
Restricting wave vibrations to one plane
32
What is current electricity?
Flow of electric charge through a conductor
33
What is static electricity?
Stationary electric charges
34
What is electric field?
Region around a charge where force is exerted on other charges
35
What is electric potential?
Electric potential energy per unit charge
36
What is capacitance?
Ability to store electric charge
37
What is inductance?
Property of a conductor to oppose changes in current
38
What is alternating current (AC)?
Current that changes direction periodically
39
What is direct current (DC)?
Current that flows in one direction
40
What is a transformer?
Device that changes voltage levels in AC circuits
41
What is electromagnetic induction?
Generation of electric current by changing magnetic fields
42
What is Lenz's law?
Induced current opposes the change that caused it
43
What is radioactivity?
Spontaneous emission of particles or energy from unstable nuclei
44
What are alpha particles?
Helium nuclei (2 protons, 2 neutrons)
45
What are beta particles?
High-energy electrons or positrons
46
What are gamma rays?
High-energy electromagnetic radiation
47
What is half-life?
Time for half of radioactive nuclei to decay
48
What is nuclear fusion?
Combining light nuclei to form heavier nuclei
49
What is nuclear fission?
Splitting heavy nuclei into lighter nuclei
50
What is binding energy?
Energy needed to separate nucleus into individual nucleons
51
What is an atom composed of?
Nucleus (protons and neutrons) surrounded by electrons
52
What determines an element's chemical properties?
Number of electrons in the outermost shell
53
What is electronegativity?
Tendency of an atom to attract electrons in a bond
54
What is ionization energy?
Energy needed to remove an electron from an atom
55
What is electron affinity?
Energy change when an electron is added to an atom
56
What is atomic radius?
Distance from nucleus to outermost electron
57
What is the octet rule?
Atoms tend to gain, lose, or share electrons to have 8 valence electrons
58
What is hybridization?
Mixing of atomic orbitals to form new hybrid orbitals
59
What is VSEPR theory?
Electron pairs repel and arrange to minimize repulsion
60
What is a hydrogen bond?
Weak attraction between hydrogen and electronegative atoms
61
What is van der Waals forces?
Weak intermolecular attractions
62
What is a dipole moment?
Measure of charge separation in a molecule
63
What is Le Chatelier's principle?
System at equilibrium responds to stress by shifting to relieve stress
64
What is activation energy?
Minimum energy needed for a reaction to occur
65
What is a catalyst?
Substance that increases reaction rate without being consumed
66
What is reaction rate?
How fast reactants are converted to products
67
What factors affect reaction rate?
Temperature, concentration, surface area, catalysts
68
What is equilibrium constant?
Ratio of product concentrations to reactant concentrations at equilibrium
69
What is entropy?
Measure of disorder in a system
70
What is enthalpy?
Heat content of a system
71
What is Gibbs free energy?
Energy available to do work in a system
72
What is an oxidation reaction?
Loss of electrons or increase in oxidation number
73
What is a reduction reaction?
Gain of electrons or decrease in oxidation number
74
What is an electrolyte?
Substance that conducts electricity when dissolved
75
What is electrolysis?
Using electric current to drive non-spontaneous reactions
76
What is a galvanic cell?
Device that converts chemical energy to electrical energy
77
What is standard electrode potential?
Voltage of a half-reaction under standard conditions
78
What is molarity?
Moles of solute per liter of solution
79
What is molality?
Moles of solute per kilogram of solvent
80
What is normality?
Equivalents of solute per liter of solution
81
What is colligative properties?
Properties that depend on number of particles, not identity
82
What is osmotic pressure?
Pressure needed to prevent osmosis
83
What is vapor pressure?
Pressure exerted by vapor in equilibrium with liquid
84
What is Raoult's law?
Vapor pressure of solution equals mole fraction times pure vapor pressure
85
What is a buffer?
Solution that resists pH changes
86
What is the Henderson-Hasselbalch equation?
pH = pKa + log([A⁻]/[HA])
87
What is a titration?
Process of determining concentration by adding known reagent
88
What is equivalence point?
Point where moles of acid equal moles of base
89
What is an indicator?
Substance that changes color at specific pH
90
What is organic chemistry?
Study of carbon-containing compounds
91
What is a functional group?
Atom or group of atoms that determines chemical properties
92
What is an alkane?
Hydrocarbon with only single bonds
93
What is an alkene?
Hydrocarbon with at least one double bond
94
What is an alkyne?
Hydrocarbon with at least one triple bond
95
What is an aromatic compound?
Compound with benzene ring structure
96
What is isomerism?
Different compounds with same molecular formula
97
What is stereoisomerism?
Different spatial arrangements of atoms
98
What is chirality?
Property of having non-superimposable mirror images
99
What is a cell?
Basic structural and functional unit of life
100
What is the cell theory?
All living things are made of cells; cells are the basic unit of life; cells come from other cells
101
What is the difference between prokaryotes and eukaryotes?
Prokaryotes lack membrane-bound organelles; eukaryotes have them
102
What is the function of the cell wall?
Provides structural support and protection
103
What is the function of the cytoskeleton?
Provides structural support and helps with cell movement
104
What is the endosymbiotic theory?
Mitochondria and chloroplasts evolved from symbiotic bacteria
105
What is cellular transport?
Movement of substances across cell membranes
106
What is facilitated diffusion?
Passive transport using membrane proteins
107
What is endocytosis?
Process of taking materials into the cell
108
What is exocytosis?
Process of releasing materials from the cell
109
What is the cell cycle?
Series of events leading to cell division
110
What are the phases of mitosis?
Prophase, Metaphase, Anaphase, Telophase
111
What is cytokinesis?
Division of the cytoplasm
112
What is apoptosis?
Programmed cell death
113
What is cancer?
Uncontrolled cell growth and division
114
What is a mutation?
Change in DNA sequence
115
What are the types of mutations?
Point mutations, insertions, deletions, chromosomal aberrations
116
What is transcription?
Process of making RNA from DNA
117
What is translation?
Process of making proteins from RNA
118
What is the genetic code?
Set of rules that determines how DNA codes for proteins
119
What is a codon?
Three-nucleotide sequence that codes for an amino acid
120
What is gene expression?
Process by which genetic information is used to make proteins
121
What is gene regulation?
Control of when and how genes are expressed
122
What is epigenetics?
Changes in gene expression without changes to DNA sequence
123
What is biotechnology?
Use of biological systems for technological applications
124
What is genetic engineering?
Direct manipulation of genes
125
What is PCR?
Polymerase Chain Reaction - technique to amplify DNA
